While it is the providers decision to post with or without pictures, I do prefer to "see" a provider prior to meeting them. The only exception is if they have consistently above average reviews. Like Superman (damn, I don't feel right calling another man "superman") stated, a womans face is of the utmost importance. Personally for me, I think a womans teeth are one of the most important features but no worries, I will not be requesting pictures of any providers showing their teeth
The problem with reviews is that us men have different opinions on just about everything. I take someone else's description of a woman very lightly as Ihave been dissapointed one to many times and I do not have the heart to just walk away so I suffer through a session...
If my opinion mattered at all, I would prefer pics or at least the agreement that after the screening process I can have a pic sent to me.