I came from a T-Mo nexus one so playing with it for two days now, some more observations/comparisons -
HTC Sense is nice, but sometimes I wish for the stock Android. You can't disable it (those sites showing stock Android is basically just a theme, not really disabling sense). Example - the gallery connects to Flickr and there's no way to change it to Picasa. Having all of my photos from Picasa available on the phone was really nice.
You also cannot uninstall alot of programs like Sprint NASCAR.
The value in the ability to install any updates from Google on the N1 has gotten much higher for me now that I've been forced to use Sense and not able to change anything. Not to say sense isn't good (the clock is awesome), but still, I'd like the choice.
The notification light is ABSURDLY small. It's in the speaker of the phone that you put your ear to:
If you can see that little spot I pointed at, that's the notification light. Compared to the nexus one trackball it's ridiculous. It blinks and doesn't breath like the trackball either. And the trackball can also be set to be different colors for different notifications on the N1 (if you root). This is probably my biggest peeve with the EVO and it really makes me want my N1 again.
The trackball also makes it alot easier to play certain games (like Frozen Bubble).
The larger screen makes software keyboard much more friendly. In the past, regardless of how good the software keyboard is on any phone (iPhone included), it was never as good as a nice hardware one for me. It was the same with the Nexus One. The bigger screen on the EVO makes it about even for me whether to prefer a software or hardware keyboard now.
The softkeys at the bottom are much, much better than the N1. N1 you had to use the top half of the key, the EVO works as it should.
Camera is alot better, when you push the take photo button the snap is almost instant. But having to use the screen to take a photo is not that great (trackball sadness once again).
Video is just slightly better (but still not great).
Not sure if there is anything else anyone would like to know. Sprint TV and Youtube and all that all work fine/look good.
Edit: Battery life is better than the N1 for me. Use it casually throughout the day and has lasted all day.
In the end, if there was a Nexus One on Sprint would I still pick the EVO? I'm not sure right now. The ability to get 2.2 and to do whatever I want with the Nexus One, along with the trackball, makes it very compelling for me personally. Unfortunately I was forced to switch because T-Mo sucks so badly for me.