As another 1K/EXP (at least through 2011), I'd join the near-consensus in terms of maintaining EXP and 1K status. The CO merger should alleviate the relatively poor position UA is in for FFs based in the NYC area. While the OP's travel preferences and patterns naturally make this a YMMV situation, I find that having status and accumulating miles on both airlines naturally opens up more upgrade, routing, $-saving and mileage vacation options.