I didn't want to speak on this subject untill I've seen more info on the US phones (and yes, the US phones are quite different in both hardware and software as compared to the EU ones).
first off, the SGS2 was my top choice for my upgrade (probably due to all the hype...note, I didn't say reality, I said hype). still today I like what sprint is going to offer. the T-mobile might not be fully ready, but it should also be great. the AT&T phone is the closest to the EU phones with basicly the same hardware (including radios and screen) and seems to be also OK.
but now I'm going to tell you what all the testers are not saying to you in all the videos that you have seen on review sites across the web...
while I love the idea of the phone, it has some flaws that may or may not be deal breakers to you.
first off, while some peoples eyes are not able to see the difference between a qHD screen and a 800x640 screen when it comes to jaggies in games, text, and movies, I personaly can. the difference is not night and day when it comes to movies or type, but it can be much sharper and a lot less eye strain for people who can tell the difference when using a higher res screen. when it comes to games (and I know that many of you don't play them), there is a night and day difference even if jaggies don't bother you much and is not a distraction.
when inlarging type (say when you are reading an e-book or website), a higher res is always prefered. this is why we have 1080p TVs today. otherwise, why not stick with 720? (more important for movies and games then type, but yes, higher res is always better)
a higher res screen phone (with the same hardware inside) is always going to run slower then a lower res screen. so when you see benchmarks and they open the phone app or any other app and the evo3d is .1 or .2 seconds slower, bare in mind that it is running a higher res screen (and with all the bloat that makes Sence 3.0 so awesome for new and old android users)...and is a .1 or .2 second difference when opening your phone app really going to be noticed in real life when you only have one phone in your hand?
in head to head testing of web site loading on wifi, the evo3d mostly looses the tests but sometimes even beats the SGS2. when it looses, it is only by a moment or two AND IS DOING ALL THIS ON A HIGHER RES SCREEN. so is web exceleration a gimic or just not as advanced as all the hype claims? I'll let you think about it and deside.
if the software for website use is more or less the same on the US SGS2 phones, then the SGS2 phones wont be able to auto wrap type. at best you will now have a button on your screen and will have to touch that to wrap the type to fit your screen. the evo3d auto wraps type by default on all websites, not just web friendly ones. so to me, when reading the web on my phone, the SGS2 is far less polished.
so when it comes to many of the review sites, many of the flaws are not spoken about the SGS2 phone and results can at times be biased.
cameras I'll call a draw due to the sammy phone sofar doing great with their camera hardware and software, but the evo3d can take 3d photos and videos. I'm a real photographer and know that MP don't mean anything and a better censor and software is far more important. the rest is just hype to help sell a phone.
radios is not the stong point of samsung, but then again, hTc is not on the fore front as well. but if I had to choose, I'll go with hTc over samsung every day of the week based on history.
when it comes to updates (both for operating systems and/or bugs) samsung has a poor history. hTc has a great history.
(note: comparing a locked or semi locked phone to an unlocked one, no longer has anything to do with the companys that makes phones and is dependent on the open source community)
hTc already updated the evo3d 4 times that not only included the OS but also a ton of bugs.
I'll bet that even boe would agree with me that a working phone is far more important then a non working one, so updates to the OS is far less important then fixing major bugs.
regardless, 4 updates total and one of them going from 2.3.3 to 2.3.4, all in under two months is something that other phone companys need to learn to do.
so with all this said, I still like the SGS2 phone. I'm even trying to push in on my nephew.
but when I got a great working phone that has almost no problems (mirror is gone, but I never used it anyway, and I can't use the new 4G radio update due to it makes my camera no longer work. but my radios work beyond awesome, so who cares), why should I temped fate and try a phone that is no better then mine?