As a Bills fan, I would have taken Romo, but the Bills have a completely new coaching staff, and a different mentality than Dallas.
JJ definitely seems to be losing his edge, though. Not sure I would have signed Romo for a 6-year extension, but given the fact they couldn't franchise him in 2014, this was probably his best move for a quality QB. Surround him with better weapons, and give him a shot of "clutch gene", and Dallas will be fine.