there is so much OP weapons, i don't see the point of nerfing this one more than any other, or you'll have to rethink mostly all weapons.
and as said before, in a good team, (thought to perform both mission and antag or at least worse antag situation), there is no real problem.
yes, you can always fight an impossible player who destroy you (that's the point of pvp). but IMO most of the time when it happens, that's because of a bad team and not so much because of the antag.
i remember a battle on beast' lair, against a valeria and shakura. none of us could pass through the first bridge. never.
fault is on us.
we had no one who could face that situation.
now i always take a character able to handle it if no one in the team did and that's all...
there is so much situation i can witness where even high grade players, don't even chose their character depending of the mission or the antag... or not knowing what there is to do on the mission...
i witnessed *1 players who didn't even knew they had to shoot the flowers in mission "double agent" (not sure of the name) and we lost because they did not shot it before shneider cut the antenna (it happens 3 fckg times, each time with *1 in the team, who all had weapons able to shoot the flowers what i had not).
now on that mission i always take a character able to handle both antag and flowers.
because i just learned, most of the time, you can't count on your mate in this game.
most are just able to kill grunts, cry about antags and ask for surrender when difficulty appears.
well it will be harsh, but all that to say, if no one in your team was able to handle her, it's mostly the fault of your team not of the weapons.
with time we'll learn what are the biggest danger on each map and think about ways to counter them, that's all.
for example, right now i still don't know how to fight against ayana.
but i'm keeping hope, one day i'll understand ! ^^
and remember it's a pvp game, it's not a "raiders will always win because we're nice people" game.
moreover everyone can buy valeria and obtain shakura pretty easyly.
if you think it's absolutly op, take her, and make those damn antags to spit their blood.