Yes, there is a difference, but what I mentioned is not that. A min-maxed specialist is not a munchkin. A munchkin breaks the rules, a min-maxed character stays within the rules. A soft maxed edge helps to confirm the shot.
I consider having nothing but 1s and 5s to be munchkin. I also don't see any reason for edge for a sniper. The character has something like 16 dice to shoot, and the target won't even get a chance to defend themselves. I hardly think any extra dice are needed to 'confirm the shot', and 1 edge is as good as 20 for rerolling if you totally botch a shot.
Like I said, what you're saying isn't anything to do with character effectiveness, it is entirely to do with costing as much karma as possible.
As I keep saying, unless you go out of your way you're going to get a better/cheaper character out of karmagen.