Now that both APDS and explosive rounds are Chargen available, lets compare the two and find out if either of them is mechanically superior to the other.
Let's start with how hard they are to get.
APDS is 12F to EX rounds 9F. This means that EX rounds are significantly easier to acquire (25% easier, to be precise).
APDS cost 120 nuyen per ten, to EX's 80 nuyen per ten. that means you get 50% more EX rounds for the same price.
Already, EX is looking better for suppression fire and automatic weapons purposes. If you're going to be firing a lot of them, the cheaper and easier to get ammunition has an advantage.
Now both of these rounds are noticeably more expensive and harder to get than regular rounds. Is the advantage they offer worth the extra price and hassle?
Well, EX rounds give +1 damage and -1 AP, while APDS simply gives -4 AP. Now on the surface those two sets of numbers come out as about the same against most targets. Right?
Let's look at some common targets to end up downrange of runners. For these tests we'll be using an Ares Predator heavy pistol, something almost every runner has or can get without much difficulty. Base damage is 8p, base AP is -1.
Target number 1: guard dog.
The guard dog has no armour, making all armour penetration modifiers redundant. as such, Explosive rounds win this one hands down. Technically Flechette rounds are superior to both in this instance, but that's beyond the scope of this thread.
Target number 2: Doberman Drone.
A standard Doberman drone comes with 4 points of armour. The APDS rounds are punching right through that and are in fact over-penetrating due to the power of the pistol. That means that our bullets are wasting some of their potential. Explosive rounds, on the other hand, are hitting with full oomph and not wasting anything, making them superior in this situation.
Target number 3: Corpsec with Armour Vest.
At armour 9 both rounds are doing physical damage if they hit, neither round is overpenetrating... both rounds are fairly even in this instance.
Target number 4: Ganger with Helmet and Armoured Jacket.
Our target has an armour value of 14. For our Explosive rounds to deal lethal damage the shooter needs to get at least 3 net hits. Not exactly a tall order, but still necessitating at least a bit of skill behind it. APDS on the other hand will punch right through if you get even a single net hit. This one depends on how your GM runs grunts (Note: with the mowing them down optional rules special ammunition is a waste of money), and from that whether dealing physical damage instead of stun makes any difference.
Target number 5: Ares Roadmaster.
An Ares Roadmaster has 18 points of armour and is immune to stun. EX rounds need 7 hits to have a chance of doing damage (capping the weapon's accuracy), while the APDS needs a mere 5 hits. Either way the soak pool is large enough to make your attack into scratch damage, but the APDS is superior in this instance.
Target number 6: force 6 spirit.
12 points of hardened armour. Now with a single hit both of these rounds will be dealing damage, but lets break it down:
EX: 10 damage, -2 armour. Hardened armour 10 automatically gets 5 hits, reducing the damage by half before soak is even rolled. With something like 16 dice to soak the remaining 5 damage, on average our spirit no-sells the hit.
APDS: 9 damage, -5 armour. 7 hardened armour auto-soaks 4, leaving 5 points again. The spirit now has 13 dice to soak with, leaving an average of 1 damage.
In this instance, APDS is superior.
Results: Against lightly armoured targets Explosive rounds are superior. When you start reaching medium armour the two ammunition types are about even in effect. Against heavily and hardened armour targets APDS rounds pull ahead.
IE: Against armoured targets the anti-armour ammunition is more effective. Who'd have thought it?