Personally, I wouldn't put much stock in the results. Sprint's had their version out the longest, which would generate more votes since it's a self-selecting survey. And the GSM phones don't get as much traffic here as the CDMA phones, so AT&T is likely to be underrepresented.

The customizations of the two are different in terms of software load, but they're functionally the same device with the exception of the dedicated number row on the Sprint version. And with GSM being the more predominant standard around the world, I expect you'll see more interesting ROM development on the GSM versions of the phone that might or might not work for the CDMA versions.

Now if the voters had all used all three, I'd find the results more interesting.