I worked at Radioshack for 5+ years (finally quit last year) and can definitely recommend the Galaxy S II Skyrocket. First, I have the regular Galaxy S II. The phone itself is incredible! I have stopped using my 7" Galaxy Tab and use my phone for nearly everything now. Screen quality is excellent, speeds are great (I live in the Baltimore/Washington D.C. metro area so I have HSPA+ 4G pretty much everywhere) The LTE should be even nicer for you! It's also incredibly thin (granted I had an HTC Hero before it and a Palm Tree 700wx before that). It easily makes it through a whole day on its battery and that includes using it via bluetooth in my car, browsing the web, occasional GPS, and of course some games and reading the news. My ONLY complaint is that the maximum call volume could be a little bit better (this is only when you're holding it up to your ear, the speakerphone is pretty decent). I used to love HTC phones, but the software has become problematic for a lot of people and the phones are a little heavier. The Samsung is an all-plastic body, but it doesn't feel cheap. I believe the Galaxy SII's all use Corning's Gorilla Glass, but I could be wrong.
And if me saying it isn't enough, my wife tells me I'm now addicted to my phone so maybe that gives you some context for my opinion of the Galaxy SII!