I hate undefeated streaks, they are a pain in the ass to book so it's almost impossible for them to end up well.
If a streak works, then it's very likely the wrestler will be too attached to the said streak - meaning that's all he has - so when he finally loses he'll probably wont have anything to fall back on. He either needs to be very fukking talented or need real good booking to overcome that loss (Angle and Punk come to mind).
I have no problem with wrestlers beating a lot of people, but when the main focus is on a streak...eehh, not a fan at all.