My dad had the signal issues with his first Fascinate. His replacement is working quite well. My Fascinate has also been pretty solid since day one, but I tweak, mod, and monkey with kernels and roms and such on it frequently. Nevertheless, it treats me quite well.
My sister had hers replaced, and her replacement so far has been quite good. My brother hasn't had any issues with his from day one either. He loves it, so far. A co-worker has had nothing but problems with hers though. She had trouble with stock 2.1. The phone continued to get slower and less responsive, despite the OTA updates they released. I cleaned it off for her and put the EB01 leak of froyo on it. She loved it ... for about two days. Now, to no fault of her own, it's getting slow and sluggish again. And the stock email app doesn't erase emails. At all. I'm worried that her phone might be defective beyond the software.
As for my wife's phone, hers ran fine and things worked with both 2.1 and the 2.2 leak that's on it now. It's fast, stable, and responsive, but her battery life is CRAP. I don't understand it. It has the same launcher as mine, it's only a couple weeks old, it has the same leaked 2.2 build, and it has the same conservative battery settings. She went to bed with it at 56% battery life. It died before morning. I've NEVER seen my Fascinate do that, regardless of build.
It's disheartening the high failure rate, but it seems that if you get a good one, then it's really a super awesome phone. I sure love mine. It's nothing short of an amazing device, and everyone is immensely impressed when I show it off to them.
Interestingly enough, my dad had the white one from Best Buy, and his was having those signal issues. His Fascinate couldn't pass the "Eagle Pass Test" in Wyoming. It dropped calls there every time, and he consistently ran on only one or two bars. My Fascinate never drops calls on Eagle Pass. He got the white one replaced with a black one because that's all Verizon could give him. The stores simply don't stock the white ones. Best Buy does, and he was outside Best Buy's return policy, and thus had to get the return on the 1 year hardware warranty.
They did let him keep the white backplate.
I'm kind of jealous. My black backplate shows scratches and smudges galore, hehe.