It's not as simple as that, "a good amount" being such a relative description. I think that's also why TTC is able to advertise that they have quiet trannies. Relatively speaking, they do. Not compaired to a T5, but compared to an 18 wheeler, yeah...
You are going to get a vibration- and possibly some noise- from any aftermarket shifter, or any stock shifter that has had the vibration isolator removed. The explanation should be fairly obvious. It isn't a Tremec issue. The howling/whining however can be. It seems as is having it, and not having it, are both perfectly normal. Be concerned if you hear grinding, clunking, the shifting becomes notchier, it doesn't stay in gear, etc. However, looking at your sig, I'm not sure any of this or even this thread is relevent to you. Why do you ask... what's your situation?