And if so, what do you think?

The rule I'm talking about changes ranged combat from an opposed test to a success test with the threshold being the range +/- any modifiers.

We swapped to this rule before it ever saw print. It's been working just fine for my group for quite a while now.

What was your reason for using it? And what do you see as the pros/cons for using it rather than the "real" rule.

Less die rolling can really speed up game play. As it stands there are two die rolls on a miss in shadowrun, and three on a hit, this reduces it to 1/2.

And since shadowrun die pools are large, this can speed things up a lot.

We swapped because it didn't take us long to realize that taking one, two, or three dice wasn't anything to really worry about for a professional-grade character, especially if you still have Edge left. We did the same thing with wound penalties for the same reason.

I fail to see why people trip about his, btw. Every single time it comes up people are all moaning about how threshold range bands screws everything up and how wound penalties being thresholds makes for a "death spiral" and blah, blah...piss, moan. First off, you don't see much in the realm of range penalties anyway unless your GM is a putz and doesn't know how big things are IRL or you're using handguns all of the time and porkchop your shadowing or infiltration rolls regularly. Secondly, it plain ol' hasn't happened. That's right, I'm a middle-low end roller more often than not and I and the rest of our group haven't been heinously hosed by either the range penalties or been caught in a "death spiral" due to these rule changes with my group.

If anything, I think it makes the game better because you have to plan a bit more to get close for that good shot and use better tactics to not get that penalty by getting wounded.

So the defender doesn't get a chance to dodge at all? No reaction either?

It's actually quite close to the TN system. Under TN, a straight shot with no mods was a slam dunk. Pile on just a few mods though, and your chance to hit is practically nil. Just having the enemy target in good cover makes a threshold 5, add some vision penalties and even the best streetsams in the world are only going to hit if they get lucky. In fact, it's probably even less forgiving than TNs, because TN modifiers were generally smaller than the dice pool modifiers, and included such negative modifiers as "attacker stationary" and "target stationary."

I think the rule works if you want an essentially realistic fight system. If you're at close range and nobody's moving or in cover, you'll hit. If there's movement, poor visibility, or cover, almost all shots will go wide. I don't know the stats, but IRL the vast majority of bullets are a complete whiff. That can still be represented by the normal system, but not when your fighting grunts, they don't have high enough defense pools to make it happen. It reminds me of a scene from The Wire. The badass assassin guy is on the road to revenge, and the way he kills one of his enemies is by hiding in a doorway and shooting him point blank as he walks past. In the ensuing firefight, taking place at 10 yards or less, all bullets miss except one that hits a guy in the ankle. And this guy is pretty much the most deadly fighter on the streets.

Now, the problem with the rule is that an unplanned firefight can turn out to be a huge waste of time, people will just waste ammo on each other all day since they haven't set up a situation where they can hit. But it certainly limits the smash-n-grab style of running -- if you break down a door and start shooting, if you don't kill every enemy before they move, you're going to die -- standing there in the doorway, if one of them full-narrow-bursts you, you're screwed.

Ahhh, I see now...I was thinking on the range was the threshold and everything else was the same...yeah, I could see this being pretty interesting. For my NPCs who usually have crap in the way of reaction, just having a 3 threshold (cover and short range) would be tougher than what my players are normally up against.

It would also make damage a lot less, as its not being stepped up nearly as much...

I don't like this optional rule. Ambushes don't get any benefit unless you introduce another rule saying they do. Also the threshold and negative modifiers can be minimized just as easily as in the default system at least by PCs.
Range? Use scopes/Image Magnification Devices and Improved Range Finders, for the combat monsters take Krav Maga.
Poor Visibility? Use Visual Enhancements.
Cover? Flank or use grenades. BTW How do you balance those in this ruleset?

Not at all. We just apply an additional Threshold modifier for range to the existing equation. If a character is shooting at Short range then it's completely normal. Everyone dodges, takes cover, etc as in RAW. However, once you get into Medium range you need to beat your opponent's defensive roll by an extra +1 Threshold to reflect the added difficulty of getting good hits at longer ranges, winds, whathaveyou.

We don't allow the "range is free with a scope" so range penalties pretty much stick around for us.

Also, scopes (besides Reflex scopes and a few Red-Dot/Collimating sights) can't be used too well while moving. If you're sitting there and aiming as a free action, you're still just sitting there. Since range isn't free and we play a pretty realistic LOS, scopes don't tend to be too handy anyway as the ranges are usually across the street at the most.
Poor visibility? Depends on what causes it, really. Natural or low-enders? Probably Ok with the right gear. If it's pros though, all the Visual Enhancements in the world won't do you much good.
Cover is cover. The answer is always team up and flank or use grenades. Nothing new here at all. And we balance grenades by simply telling the players that what they bring, the GMs get to bring. You want to roll grenades into someones lap while they sit at a red light? Fine by me. Just don't be surprised if I return the favor, friend.

Then, what do scopes do at your table?

Nothing except another houesrule forbids you from moving, stopping, aiming and shooting and moving again. Where is the problem?
How are visibility modifiers different if the opposition is more professional?
Correct, I just mentioned it for the sake of completeness.
I consider that a given anyway. Within a realistic budget and if the organisation has the right skills, the opposition will get the most effective defensive and offensive measures at their disposal. I'd go even further and say they will do that whether the runners use intelligent tactics and big guns or not.
With your houserule however airburst grenades are even deadlier than in the default system. With 3 (net) hits airburst grenades from a launcher always explodes in the same action phase directly on the intended target. 10P AP-2 and lesser damage in the vicinity is pretty bad. Not to mention that you can shoot 2 grenades per phase. Moreover you needn't use lethal ammunition.

Scopes, with a decent weapon skill roll, reduce the modifiers for a shot at medium or longer ranges by one bracket.

Pros will use hot smoke instead of cold smoke. Flask packs and/or flash-bangs will also be used by pros to screw with your senses as well. Little details and improved equipment, basically.

You mean to tell me that the single best improvement in per-man lethality in the last 70 years might be dangerous? Of course airburst grenades are going to kick some serious butt, that's why they designed the dang things. I would also make it a lot less than 3 net hits to blow that puppy right on top of you. It shouldn't take a average-to-hard difficulty test to have your weapon work properly after all. Just lase (aim with a simple action), offset(free in AR), and fire(simple action) to get that puppy right where you want it.

Reducing efficiency of supplementary gear to reduce the deadliness of your rule appraach? Not necessary in my opinion, but if your players like it, have fun.
BTW what have you ruled for the improved range finder?

The increased drawbacks for the opposition apply to the users of such devices as well. With ultrasound, thermographic and Low-light vision, you should be pretty well prepared for most situations. I have not looked at the rules for RADAR yet.
Depending on the targets your runners hit, most of the time it is more believable that the runners have such gear than the opposition.

The three hits are only for the worse case scenario, where the scatter die shows a 6. Net hits however have no impact with grenades (as per SR4A). I agree that airburst grenades are deadly and should be, but from a rules point of view it irks me that a moving target is hit just as easily as a target lying around unconscious.

As my standart eye package includes low-light vision, eye light system and flare compensation, thermal smoke is only -1 more than light smoke and same as heavy smoke(witch one of those does a smoke grenade cause?) and flash-bangs don't do anythink.