Sounds to me like you need to bring your bike in and have it checked out. If you already have, maybe you need to take it someplace else. There are probably a bunch of wrench heads in this forum that can suggest some things to check yourself. You said the top speed sucked but you also said you were too concerned about the vibration to get out of fifth gear. Sounds like the real problem is the vibration. I have a friend who had a SV and it wasn't exactly slow both in town and on the free way. However, he did trade his sv in for an aprillia falco because he wanted something with a lot more power. I've been on organized sportbike rides where experienced guys on sv's were able to stay with other people on various types of bigger sportbikes. I'm talking about high speed country road riding. This leads me to beleive that there is something uniquely wrong with your situation. Might be worth not getting rid of the bike just yet.
It is easier to get forgiveness than permission.