I've been using Android phones since the original G1 and mostly have been sticking with Samsung phones. Captivate, SII, Skyrocket...I had a few mistakes when I tried the Motorola Backflip...ew. And an iPhone or two...hated them.
GPS is much better than Samsung
1.14 sucks. I miss being able to download ROMs on the go and flash them while sitting in traffic.
Removable battery. I liked being able to have an extra battery or an extended battery. I might go with one of the skins that have an included battery though.
Removable storage. I also liked being able to throw a MicroSD card in.
Battery charging location. I HATE that it's on the side. Makes it a PITA when trying to put it in a dock or use it while it's plugged in ...especially if the charging cable is on your right...
No supported version of CWM
Probably going to go back to Samsung when I get a chance. I love this phone, it's very nice and elegant but Samsung phones are just more flash friendly, IMHO.
Great phone though.