Here's more on the LTE version of SGS2:
Samsung Galaxy S II with Motorola Droid Bionic like feature unearthed
Not much, but the LTE version apparently supports a 1750mAh battery instead of the SGS2's 1650mAh.
WHICH MEANS TO US: LTE and a probably better battery equals great data rates and longer life! I think the Bionic is looking cheesier by the day, if the Stratosphere is anything like this baby. And I'd like to think it is