Nokia N95 8GB, Samsung Focus, Samsung Galaxy S Captivate, Samsung Galaxy S II LTE
Samsung Galaxy S II LTE
Since it seems that no one else has responded to your query, I'll give you my take, though you might find it less than useful given that I'm not on AT&T, but rather on Rogers in Canada.
Up here Rogers calls the phone the Galaxy S II LTE, but it's still a i727, same as yours. However, Rogers doesn't market the phone with the same level of bloat as you generally see on AT&T, but bloat in and of itself shouldn't make a phone any less useful.
Right out of the box the S II LTE (Skyrocket) is a hugely capable phone and it handles SMS, MMS, and music (as do all phones really). It also comes with the Gmail app (just as all Android phones do). If you want to sync with a Microsoft Outlook server, I believe you need to get 3rd party software, but setting that up apparently isn't a huge issue.
Beyond those 4 basic things, are there any other features you want to know about?