I played with an iPhone 4 and HD7 today and was so impressed with how much more fluid, responsive, and smooth they were. They made my Droid X running a vanilla ROM with Launcher Pro seem a little sluggish. The transition animations we're just beautiful too. What I likes best were the web browsers on each. They were so much smoother than all the browsers on Android.
Granted I still love my Droid X and open source capabilities. But I really hope Google wil hurry up and polish Android more. Windows Phone 7 just came out and even though it's still limited and in it's infancy, it's just more polished than Android. The thing seemed even more responsive than the Tegra 2 LG Star that isn't even out yet just basing off videos.
But this just means Google has to work harder. Enough of the skins!!! Give us stock Android!! If all the new devices release with skins I'm just gonna put vanilla Android roms on them anyway.
But yeah as you can see I was really impressed with both other OSs and just want to see more improvement on Android.