No one can tell you with any certainty what any of these programs will be doing in 6 months, much less 2-3 years. For example, right now there's ongoing talk of a US/AA merger, and if it happens, that would change many things in terms of alliances and redemptions.

Amex points are good...less so than they used to be maybe, due to fewer partners, but still flexible. Chase UR points are a pretty good option these days, lots of transfer partners. If you're willing to commit most of your spending to one card, you can find one that has a companion pass deal (I think the BA card does that after $30k?).

Sorry this isn't more of a direct answer, but unless you have one specific destination/goal in mind, it's hard to say that one choice is better than another.