I'm not getting any new phone. My upgrade is in 7 months but 2.2 has just about everything I want now so I could care less about new phones.
And what makes Sense more polished than stock? I've never used Sense so I don't know. But some people stated that Launcher Pro adds a Sense-like experience. Everything is just as quick and snappy as on the Incredible and my Droid isn't even overclocked.
I think 2.2 pretty much finished a lot of the kinks left with 2.1. Stock 2.1 was okay but definitely needed some improvement and all of that seems to be fixed with 2.2. Add a custom launcher to that and it's even better. I think your opinion on stock would change if you used a Droid running 2.2.
Either way, we have varieties so it's all good.
I've used a Nexus One, so I'm sure it is at least comparable.
And yes, 2.2 feels much more finished than any other version of Android.
But it still lacks some of the eye candy that users have come to expect from OS's like webOS and iOS.
But you are right. Variety is what makes Android so unique. Personally, I'm waiting for a root to throw 2.2 on the thing. But I still feel that Sense UI is better for normal consumers.
To each his/her own.