With that mix and the LAX base, I'd probably go AA.

Pros are the 100% earning at Plat and the easier use of SWU's. In general, if you think long-term you're more of a 50k guy than a well-above-100k guy, AA is probably better than UA.

Cons are the total breadth of Star Alliance vs. Oneworld and, to some extent, the raw size of the airline in terms of your own "native" metal.

My own anecdotal experience is that I can upgrade more as a low or mid tier elite on AA than I can on UA. The requirement for low/mid-tier to actually click a checkbox to upgrade seems to work in my favor, whereas United's UDU process just fills the F cabin with the higher tiers automatically.

If you were SFO base, might be easier to make a UA case. Out of LAX, I think AA is a solid choice.

So how do Avios work if I am looking to spend them stateside? How would I book an award ticket with them exactly? Just trying to wrap my head around the program because it looks like a good deal. Definitely like the One World partners as well.

You can book them on ba.com. BA avios is now great for small nonstop flights in the US.

You'd log in to your Avios account and book them from there. It's distance-based. A short-haul on AA would cost 4,500 miles each direction up to a certain number of miles (I forget the exact cutoff distance).

Short-haul nonstop = sweet deal.
Long-haul nonstop = probably a similar deal to what it was before, with some exceptions.
Long-haul with connections = probably a bad use of Avios, again with some limited exceptions.

Lots of grumbling on these boards about the program, but AA short-haul remains a good value in many cases.

I tried and got this:

Error

British Airways does not have traffic rights to operate directly between these two cities.

Are you logged intovthe avois page and have you selected book with avios?

I am now - I was missing that part. Thanks for the help!

We have all done things like that.