If I'm O'Connor, I'd be signing with the Rangers.
(1) For development purposes, Benoit Allaire = Rollie Melanson. In fact both teach the exact same techniques (deep in crease, butterfly, controlled movements, efficient use of energy, blocking the puck vs. saving the puck, etc. and both have a Vezina goalie to their credit). Perfect style for a big-bodied goalie like O'Connor.
(2) For opportunities, Henrik Lundquist is 33 YO and has four years left on his contract that takes him out to 37 YO, just in time for him to pass the throne to the next starting tender. If O'Connor plays his cards right, he could be that guy in four years in Manhattan. For all intents and purposes, Vancouver has Miller for two more years, and following that Lack for say another 3-5 years (five to seven years of potential goaltending stability in Vancouver). After Lack is done, Demko is in the pipeline and the "next one".
Obviously this is how the landscape looks right now and lots can change, but this could very well be the way O'Connor may be looking at the present and the future.
As well, O'Connor attended the Rangers development camp, so the fact he was in Vancouver last summer is pretty much neutralized.
Edmonton's got squat for goalie development right now (two "consultants" who resume is "teaching" 16 to 18 year olds).
Ottawa just started negotiations with Hammond, and they already have Anderson and Lehner under contract, and their goalie coach is Rick Wamsley (don't know anything about him as a coach, so can't comment on his proficiency as a goalie developer, but it seems Ottawa develops good tenders...e.g., Ben Bishop).