VC money, a good team, or a great product won't guarantee success. One (or two) factors alone won't ensure success. It's a sum-of-all-the-parts thing. I think an important question to ask yourself is: how committed are you? Not so much: then spent your time, money and energy elsewhere. Very: then do a detailed (honest) analysis on your product and theirs and if it still makes business sense, keep at it. Sometimes it how much pain you're prepared to endure... or is that running? :)