First, let's assume you can get either a status match or pass a PLT challenge. Challenges completed in the 2nd half of the year preserve status for the entire following membership year (to Feb 2011 for latter 2009).

At this (middle) level, the UA and AA upgrade systems are broadly similar--- using 500-milers with a 72-hour window. If you happen to be on a Y or B fare, then no 500-milers are required. On AA, the 500-miler system is valid for North America (incl caribbean, bermuda, hawaii, alaska, mexico, central america). Your top destinations are very high frequency, and so your upgrade percentage ought to be good if you avoid the peak-most flights (and Hawaii, for which you should probably upgrade by other means). At the airport, either by kiosk or in the club, you will often be able to switch to another flight and perhaps snag an upgrade that way. Although AA does not have E+, as a PLT you have advance access to exit rows and the remaining "good" coach seats. The "preferred" seating zone, of aisles/windows forward, is quite large on many flights. There should be little chance of ending up in a middle, even if buying near last minute.

Award redemptions on AA are of two types, as on UA, but now most trips are redeemed one-way, so you can mix and match award types. If you redeem an award in coach, and the load in F is light enough, the kiosk will sometimes offer you a cash upgrade option--- this is the only way to upgrade an award trip (other than op-up). For redemptions on partners, you can work by zone (all partners, one-way basis), or by mileage (oneworld partners only, but no limits on stopovers).

Long-haul upgrades cannot use 500-milers, so you need either miles, or systemwides. Mileage upgrades require a co-pay from discount coach, but if you happen to be on a Y or B fare you can use fewer miles and avoid the copay. Systemwides are free of charge (but only go to top level or 2MM flyers), and can be used on most fares, for up to a 3-segment one-way trip.

Historically AA has not used many widebodies domestically, but this season there are a number of them scheduled for it. 3-class planes (777) are sometimes sold as 2-class, with "business" part of the priority seating zone.

When there are off-schedule operations, there is some benefit to being a PLT (compare as needed to what happens on UA).

From DFW, AA runs nonstops to Europe (LHR, CDG, MAD, FRA), Japan (NRT), South America (GRU, SCL, EZE), Central America, the Caribbean, Hawaii, and Canada. HKG and SIN are 1-change via LAX or NRT, and the connections are fine for those. As PLT you get Business Class lounge access when flying internationally (not on a solely domestic travel day).

Once you reach top level, EXP, life gets easier. You no longer need 500-milers (and cease to earn them), except for companions, and the window expands to 100 hours. You get the EXP phone desk, and you get the systemwides. You also get F lounge access as available (again on international travel days only). You no longer pay redemption fees on awards at the last minute, either (whether or not the award is for you to travel).

The real issue is planning how and when you would get to top level. AA offers three methods to qualify: miles, or 100,000 "EQM"(straight-up miles, 500 per segment minimum on AA, can be less on partners); points, 100,000 "EQP" ('base miles' per segment times a multiplier of 0.5, 1.0, or 1.5 depending on fare, so the minimum points could be 250, 500, or 750 depending on fare); or 100 segments (one flight, or one 1-stop if no change of flight number). The trick is that qualification must be competing DURING A CALENDAR YEAR (Jan 1 to Dec 31). You will be given the status as soon as you reach the qualification level during the year. The qualification is good for the remainder of the current membership year plus the subsequent membership year (Mar 2010-Feb2011 if you cross the threshold during 2009, Feb 2012 if you cross during 2010). You get the 8 systemwides immediately upon qualifying for EXP.

If you can't make it during 2009, then after the challenge it would potentially make sense to do UA flying as needed to top up that total. You would then front-load 2010 to the extent possible.