Thanks to all who have taken the time to answer.
I also posted this question on Quora at http://www.quora.com/Web-Development/If-a-startup-plans-to-e....
I should have clarified that I wasn't looking for advice for a specific startup, but rather to draft up a general guide of pros and cons to consider for any startup facing this decision.
I'll absolutely take all of the comments made on this thread into consideration when I write the post!