I've shook hands with both, and Obama is much skinnier and shorter in-person than you would suspect (I still doubt he's 6'1 and feel like he's 5'11, maybe 6'). Romney has a more masculine build, is probably about 6'2 or 6'2.5, and I suspect would clock Obama in a fist fight.
As for this poll, I'd suggest doing it again after the debates to see what happens.
Fun fact after doing a quick search on Romney's reported height (6'2):
"Since 1789, the taller candidates have triumphed in 58 percent of U.S. presidential elections, and what’s more, they’ve won the popular vote 67 percent of the time. There’s even a term for this phenomenon: the Presidential height index.”"
Source: http://newsone.com/2015729/how-tall-is-romney/
Wow. This might just be the most non-self-aware hack post of the year so far.
...or pretty much any of the posts in this thread.