robyng actually has a great point- as of right now only Continental Onepass (not United Mileageplus) is currently is a part of the Ultimate Rewards program (yes you can transfer between, but there still are differences).

Chase has not, to my knowledge, confirmed that United will be a partner once Onepass is dissolved. I am hoping it will, especially since Chase partners with United for their credit cards, but you never know. Especially with the potential BA devaluation, the Sapphire Preferred card needs some new airline transfer partners once Continental goes away.