They way I interpret their service is like this: They build enough of a prototype to help you get funding. They make no mention of taking you the rest of the way. Nor do they claim to build 100% of your functionality.
If that's true, then you will end-up walking into a VC/angel office and showing the prototype. The person across the table will ask you how long it will take to turn the prototype into a launched product. So, here's the question: Can the prototype they develop even be turned into a real product or is it throw-away code only mean to help you raise money? What if they're writing crappy throw-away code and you know it, can you ask them to improve their engineering? Probably not because they're writing a prototype.
If you walk into a funding meeting with a prototype but without an engineering team, your chances of getting funded are pretty slim, IMHO. But, it is possible that a good prototype can help you attract engineers, so maybe that's not so bad.