I think UA MP still has an edge over CO OP.

The highest elite leve of CO is platinium, and that requires 75,000 miles. But that does not get you any CR1's for advanced upgrades (such as P.S. flights), and it does not get you any systemwide upgrades. To get your SWU's on CO, you still need to fly 100,000 miles/year. And even then, you only get 4 SWU's instead of 6 SWU's.

I think UA MP probably has a slight edge. Starnet blocking is a whole other issue, though.