It's like that with every new phone release. The phone doesn't meet people's crazy expectations so they just dog it, or people are Fanboys for other OS's or other manufacturers, so they'll dog this one. The same thing happened with the D1 was released.
You also have to remember that most people that are perfectly content with the phone don't feel the need to voice their opinion as much as the few that may be experiencing some problems (I am guilty of this).
There are also always going to be a few people that get a bum phone. This is the case with any mass produced item in the world.
So far I love my Fascinate. Granted I've rooted, removed the bloat, and have LauncherPro installed, however everything else has been great. Google Navigation works perfect, yes it does take a little longer than my D1 to sync up with the Sats, but once it's synced it hasn't led me astray yet.
It's been my philosophy that if it is possible for me to hands-on try it myself, I'll do that before I take the word of a few nay-sayers on the internet forums...