It's true you have fan boys here and at Rage. They're certainly on other forums too. I've used the 5870 and 5870 Crossfire X. I'm currently using a 470 and a 5870 in rig 2. Yes it's still early for the 470. I've also had a pretty good deal of experience with products from both ATi and nVidia. My card history is below.
You may add HD 5870 Crossfire, triple HD 5870 Crossfire and a GTX 470 to the list now.
I'll agree not to discount or dismiss other user's direct experiences if they will do the same for me.
If you're going to read reviews, read them all or as many as possible. It is worth repeating that bar graphs FPS reports do not tell the whole story. Some reviewers do report hitching, bugs or graphic glitches, and others gloss them over. Sometimes these issues may not crop up in canned benches which both ATi and nVidia heavily optimize for.