I bought Nexus One (2.2) and it freezes often. Called HTC and got a new one, same issue. Checked Google Android forum, many people have the same issue. So this is not a phone issue but Android issue. Eventually I sold the Nexus One and bought a IPHONE4. I hate ITunes but it doesn't freeze.
Although other features are good (flash, market etc) but what's the purpose of a phone? Making phone calls!! It's useless if it has call issues.
Android concept is good, open source but until it's stable, don't waste your money.