No, I have not been to the Maldives. I am looking forward to it.

FWIW, I always recommend not having all your eggs in one basket and at least have a backup. I fly AA and earn AAdvantage miles that way, and I have a UA MP Visa and earn UA MP Miles that way. What airline I choose as my preferred airlines depends on many factors. I live in the DC Metro area so from a convenience standpoint, UA would work better for direct flights. BUT, getting upgrades on UA is very tough, whereas my success rate at getting upgrades on AA as a Plat and EXP (alternating years) has been 100%. I don't like flying in the back of the bus, so that is top priority for me. Between upgrades and AA YUP fares, which are much more affordable than UA, the choice for me is AA. From my experience the hub airline will always be more expensive on YUP fares than the non-hub airlines. So if you live neat DFW, you will probably find YUP fares on other airlines will be much lower than on AA. Since most of my travel is personal leisure travel, the cost is an overriding factor in determining who I will fly, and when doing so how much it costs to fly in the front of the bus whether that be dollars, miles, or a combination thereof.

While I hold no status on any *A airline, I do have a stash of UA miles to use on their flights if needed. FWIW, I have never been compelled to use ST or its partners other than Continental. It is nice that they are moving to *A as I will be more prone to use them and collect miles on UA. I have found that CO miles are next to impossible to use for any desirable destination.

Now for others, flying direct flights may be more important, or being part of an alliance that has the most airlines, or perhaps their company dictates what airline they use. The bottom line is each of us has our own reasons why we use a particular airline, and just because reasons work for one person doesn't mean they will work for someone else. In other words, YMMV.