HTC One S on AT&T?

Unless pictures aren't doing it justice, I'm really dissapointed with the S3...it just doesn't look good.

So, I think I'm going to go with the One S, but the problem of course, it that in the US, we get the T-Mobile version and I'm on AT&T (also, T-Mobile Branding....eeewwww). So my questions are:

1) Is the One S compatible with AT&T

2) On a spec sheet, what should I look at which would indicate AT&T compatibility?