When i was in the T-Mo store playing with the Amaze a couple of things about it made me think it will be the SGS II for me allll the way.
The Amaze with the Black and silver trim is undoubedly the classiest sexiest phone available today, but those "My Touch" rounded corners really detracted from the form factor. Had the corners been more squared off like the EVO 4G, it would have easily made the decision between the two phones (from a design point of view) 100% in favor of The Amaze. But WITH the rounded corners, not so much....
When both phones are turned OFF, the way you can barely see the glass from the bezel on the SGSII is very sleek looking.
At the store, even with the 1GB Ram and 1.5 dual core proc power, the Amaze STILL hesitated and would say "loading" for brief moments. Didn't really care for that, considering there was barely any apps or photos or music on the thing.
The Amaze with its 960x540 res while sharper, is also longer and narrower, better for landscape, but not as good in Portrait mode as the SGSII (which is how i hold my phone 95% of the time)
Those two dedicated camera/camcorder buttons were "awesome". I really think that is its best feature, going from a locked phone to be able to catch a "kodak moment" in an instant is a phenomenal feature, but i can't allow it to influence my decision, as i use my phone for a lot more than just taking pics.
I think the Amaze is def an upgrade to the Sensation in every way, from form factor, RAM, Processing power, internal mem, the ded camera buttons, NFC Support, upgraded O/s (2.4 vs 2.3) 2MP FFC vs 1.3, bigger battery and 4G support, but from using the Samsung Epic Touch for a week (terrible signal) and now being on AT&T (with the SGS II for the past few days -4.3 screen not doing it for me : ) i just think i will choose the T-Mo version of the SGS II, i just love the way it flies
and N-E-V-E-R chokes, and the lightweigh of it, the color saturation and lastly the 4.5 inch size....
For me since i love HTC 3.0 so much, i went out and got a 7 inch Flyer tablet at Best Buy this weekend for only $299.99, and that tablet is soooo perfect it will easily tend to any & all my "HTC needs" Its kinda like a giant Amaze : )
Hope this comparison helps
BTC