I can be a pretty decent raps and I've seen people do well with them, but the ultimate glitch when it shows you use it through the walls fucks it up big time - any good player as soon as they see that can easily kill raps 9 times out of 10. If that would be fixed, I would probably agree with you there (maybe increasing crit chances wouldn't hurt either), but inability to properly hide with ultimate along with you being a 40th level easy target does make it under-powered.
Spider wasn't over-powered - good humans can kill them any day. A good player with max human + weapon + lace + health + helm = almost impossible to kill. I've seen it in countless of times of how max humans can clutch in situations any other race would probably be destroyed easily. Don't get me wrong - I'm not complaining and I have no problems with it just like I'm fine with all the other races in our server... But human is definitely over-powered.