I have a 928 on Verizon, and I've been considering switching to AT&T. Today I stopped by an AT&T store to check out the 1520 - I loved it. I found it more manageable in my hand than I imagined I might. Granted I am 6'2" (though I wouldn't say my hands are any larger than normal for a guy my size), but I did not feel like it was overly difficult to maneuver with one hand. I found the matte finish on the body made it easier to slide slightly in my hand for particularly far finger stretches compared to my glossy 928, which sticks a bit. Even with the bulky security case from the AT&T store's display I was able to use it fine.
It felt light and high quality - it's actually a little bit thinner than my 928, which again contributed to its manageability. I'm about 95% sure at this point that I'm going to jump ship to AT&T - partly for the 1520 but also just because of their superior support of WP. As many others have described, even just looking at the 1520 in the store today, my 928 seems oddly small.