I vote for #3 mostly due to feeling that if you are asking these questions instead of just jumping in and learning it, it is probably not for you. And from th

I vote for #3 mostly due to feeling that if you are asking these questions instead of just jumping in and learning it, it is probably not for you. And from the limited information you have provided, I would be wary of going forward with your 'other developer' with the platform he is comfortable with. I would think a great developer would not even put you in this kind of position. Perhaps I'm being unfair, but is there anything preventing him from making the case for a different platform or learning rails? and plus it's rails, not like he needs to crack open some COBOL.