The 900 might be a super duper stretched 737 and it might be cheap to operate but from a pilots standpoint it's still a tiny, little, cramped, noisy 737 up front with no place to store your bags. The 757 has a very nice flight deck though I can't give it any points for quiet. The 900 never a 757 will it be in range, performance or flight deck comfort.

I hate to say it but the 320 is about ten times nicer up front, especially on those rare days that it isn't broken!