if you're happy with united, earning 1.5x on everything is pretty good, even without category bonuses. what about a chase sapphire preferred instead of Amex? that way you earn 2x on travel and dining, and those points can merge with your United balance. plus primary car insurance and also the option to transfer points to Hyatt, which you get platinum status with via the club card.

i know this is the amex forum and i'm on about chase... in general, i like the PRG and use mine a lot. in this instance, though, it seems like it might be better to concentrate points around united by leveraging chase's products.