[richem]

I would definitely second the suggestion of identifying "deal breakers" as early as possible. It's much easier to highlight a shortcoming and come up with a reasonable solution when a few hours/weeks have been committed vs 100/1000's of hours.

Sales people can greatly mis-state product capabilities so be on the lookout for where they let themselves get carried away with selling a solution. I've even worked with them before and gotten called down for correcting their "misunderstandings" in front of the potential customer.

Sales people live for the sale, you should be living to deliver the final solution to a happy/content client.