Generally, I would register both domains so I wouldn't have the problem of domain-squatters stealing a domain that involves my projects/IPs.
Example: I currently have hesays-shesays.com for my podcast, but I would've gotten that AND the hypen-less one had it not already been taken by someone who doesn't use it at all. Which is really annoying =/
Well. I can see this poll is a lot of help. -points at the 50/48 split- That said, I picked altabestudio. Most websites I visit that have more than one word in their name usually register that name without dashes.