balence isnt everythoing. too much and it will make all the weapons seem more or less identical. you got to have those 1 or 2 superweapons, you may get to fire them 10 times throughout the game, but theyre there when you need em. quake 4's weapons were disapointingly over balenced, the dark matter gun was too weak, and the machine gun was too powerfull. the only time balence should matter is in multi. and frankly to give better weapons to experts seems dumb. enforcing handicaps on experienced players would make it acceptable, newbs dont get assraped as much and the 1337 can still be challenged.
i seem to like the weapons that people seem to hate, that is grenade launchers, gatling guns, merc missiles in d2 (dont know why they kick ass), fish/fire/emp, you know, things people call spam weapons. they may not be the most accurate but they always have that little tactical advantage.