The question every manufacturer of a non-Apple smartphone on AT&T has to answer is “why buy this over an iPhone?” For Samsung and most other Android handset makers, the answer is a big, bright screen, fast speeds, and all the Google integration you could want. Manufacturers are flooding the carrier with similar phones, hoping to catch buyers’ eyes with something. Samsung’s original Galaxy S was one of AT&T’s best smartphones, and managed to attract a lot of buyers — and now the Galaxy S II ($199.99 with contract) is here. It’s got a big, 4.3-inch screen, connects to AT&T’s HSPA+ network, and has a super-fast Samsung processor. But is that enough to compete with the iPhone? Is it enough to be the best Android phone on AT&T, or even Samsung’s best? Read on to find out.

(Much of this review is borrowed from our review of the Galaxy S II for T-Mobile since the two phones are extremely similar. We’ve highlighted some of the similarities and differences in each of the reviews.)