Well, I don't want to "punish" sneaky grenaders, but, seriously, do you find actual PvP interesting ? And I'm only talking about grenades. This "one burst/one shot, pawn, you're dead" thing is pretty boring, don't you think ?
That's why I think grenades should generate more damages, but in compensation grenaders 'd have to use more tactics/skills than just click 5 times in a row to kill their opponents.
It's all about positioning, if you run up and click 5 times in a row you're dead and the target might even survive if he's quick (I'm talking group scenarios, 1v1 was always about who pulls the trigger first anyway). And yeah, I find following people around, attacking from proper distance at a proper moment from an angle that makes me go keyhole on my target (ie. attacking the person I want to kill while his buddies don't have LOS on me) and, especially, withdrawing without getting killed quite interesting. I'd say it's a bit more demanding than playing sniper/bg last session (but, as Kilgore said, it gives you a bit too much of an advantage if you do it right - but it's because of how sneak works, not because of grenades).
Anyway, there's much more tactics and skills concerning the actual attack once you're in a proper position with those 5 grenade clicks than with sniper click target-click eyes routine or BG "click 3 times" because the target can get out of your range before you're done and when that happens you basically can't resolve the encounter in your favour and have to stalk again. It's more or less the same problem as with HtH. The only weapon that should be sort of slowed down (to have a dmg output more or less on par with plasma nades) would be dynacord, as with 2 or even 3 ap/throw it would be simply ridiculous.
All in all, grenades aren't overpowered even with the current sneak, they give the attacked party a chance. BG and SG don't because they can't be "escaped" as the attacks are so much more rapid and devastating and they don't have the "reach limit". You could balance it by introducing weight penalties or simply disabling sneakrunning with a 2handed weapon in active slot. It'd probably work with FOV penalties back. I just hope the devs deal with the sneak situation without axing the skill like prewipe and without messing with weapon values, as that would be the wrong way out.
Another solution would be to introduce "hearing" sneaking characters from 4x sighting distance or something like that - you see a grey figure without any indication of its weapon and armor and can't attack it, but you can take measure like avoiding maneuvres. Or make the distance something like 3x sighting and allow attacking with a humongous chance to hit penalty for first shot. Or make the minimum spot distance equal your character's PE - so it'd be 10 hexes instead for 3 for 10 PE. That last solution would probably be best since it wouldn't mess with anything too much but would make coordination so much harder it'd all boil down to player skill and coordination (remember sneakers are immensely weaker once "decloaked" than normal fighters).
