I think that as long as the keywords are strong... a "-" is fine. Just look at the jump in value of the L-L-L.com domains. A few years ago... people would have laughed at such a registration... but as the demand increases, the broader the scope of domains. Those that speculated that the "-" would become a viable option are sitting pretty... while those that were skeptical are the ones trying to obtain these babies on the aftermarket for prices much higher than that of reg fee. IMO
L-L-L are not just any word-word that's why their value increased. For development they are fine if you are willing to lose few visitors because of the dash. But for resale the dash will lower the value pretty much.
Of course it does! Hyphens dramatically reduce the value of any domain name. I would only reg hyphen names only if the domain name is a good 2 word name.