I do not believe you will be able to upgrade a US Airways codeshare flight booked on AA.com. From their FAQ:

Q: As an AAdvantage member, can I upgrade on US Airways or US Airways/American Airlines codeshare flights?
A: This is not currently an option. The same is true for Dividend Miles Preferred members – they will not be able to upgrade on American flights or US Airways/American Airlines codeshare flights. Decisions about upgrade policies will be determined at a future date. We will provide ample notice for any decisions that impact our members.

Last week I called AA customer service specifically asking about the Low Price Guarantee because I wanted to book a US Airways flight that was $100 more on AA.com. I have some AA gift cards I want to use, which US Airways will not accept. I gave the agent the itinerary and prices. She put me on hold to inquire about the policy and then came back and said the Low Price Guarantee does not apply to US Airways-operated flights booked on AA.com. She also said that in order to get the lower price, I needed to book on USAirways.com.

But if you book AA flights on usairways.com with AA flight numbers and operate by AA as OP indicated in original post he should be able to upgrade them just as if they'd been bought through a travel agency or Expedia or such. Should also have access to MCE and any other AAdvantage perks they may receive.
The only thing he'd miss out on is the $50 coupon and the 2x miles.
I personally don't think it's worth the hassle. I bought a ticket on AA.com once and found it less expensive on Expedia shortly afterwards, same flights and fare classes, etc. Sent a request fort he low price guarantee and did not get a response in a prompt manner. Ended up canceling the ticket (within 24 hours) and booking with Expedia.
Btw, do you know if they book into same fare classes/codes? This may prevent you form using the low price guarantee....

You're right. I missed the part where he mentioned it was an AA-operated flight. For this situation I'm not sure if/how the Low Price Guarantee applies.

Booked my first US*/AA operated codeshare the other day. For whatever reason US' fare on the AA flight was $145 for DEN-MIA one-way, while AA was displaying $712. Are you kidding me AA? Yes, I get this was for memorial day weekend, but seriously, $712?

Then I checked the GDS and saw that only 1 seat was left for sale in F, so no way I'll get the upgrade anyways. That was a no-brainer.

US changed it's codeshare fare the next day to $350+, so I was very glad I caught it when I did. All I need is my exit row and a free snack and I'm good.

$712, please...

So why did you put a thumbs down? Seemed like you saved a ton of money?

I did, and very glad about that. But it was a mistake on US' part that was fixed the next day. Extolling the virtues of more choice, benefits, and lower prices with this merger is absurd when you look at:

a) AA is charging that much for a domestic one-way (and I had a friend check in Sabre, there are over 95 seats still left for sale)
b) I will not be *eligible* for upgrade benefits for booking a US flight number
c) US is now matching AA's price after the mistake was fixed

Granted it's just one example, and maybe AA is truly selling seats for that much I don't know, but IMO the pricing should be a tad more reasonable than $712. I mean, I can fly JFK-LAX in first for less than that :D

Why different pricing on US and AA's website for same flight?
 

I was looking at PHL-DFW on both usairways.com and americanairlines.com. US is a lot cheaper and sells cheap flights on multiple flights, and I figure it's likely because US is matching Spirit out of PHL, maybe even trying to drive Spirit out of PHL back into ACY. However, if booked from americanairlines.com, the same US flight is much more expensive.

Example:

From usairways.com, on all or most of the US operated flights, these are fared at $74 one-way, for Wednesday May 7.
From americanairlines.com, on those same flights, Choice is $289 one-way!

I suppose the low fare seekers will check kayak and the like, and find the US Airways flight. But, what's the point of not selling it low fares from americanairlines.com if the point is to drive out Spirit? I know the FF points and plans are different, but wouldn't the US FF miles and AA FF miles merge?

With Southwest and AirTran, Southwest.com sells the same AirTran flight for more, because of the difference in bag fees, change fees, non assigned seating etc., but what's the explanation for US and AA's site to be so different?

AA ticket $548.90, US ticket $1010 - is this the biggest difference yet?
 

Booking some travel I see some surprising differences in cost! Do I have the biggest difference in fare costs yet?
http://imgur.com/BBehDBG.jpg

More importantly, $550 for AZO to ORD? I hope someone else is paying. :eek:

Ouch.

But OP, what program are you using?

Flight US3004 is busy ( F4 A4 Y4 B4 M4 H4 Q4 N0 V0 W0 L0 S0 T0 G0 K0 U0 E0 R0 ) and so the fare is high. I don't see that it is that amazing

This one is actually less odd than it looks. A bit of searching on ITA shows that AA sells a through fare AZO-ATL:

US doesn't seem to, so the US ticket is priced as separate AZO-ORD and ORD-ATL nonstops:

Those components are priced almost identically to AA, if you search for them separately (not sure I grabbed exactly the same flights):

US does have through fares on the journey.

In the tests on matrix, it is probably just finding that for the itinerary selected , combining 2 fares was cheaper

AZO - ATL for $550 Yikes. Even worse that it's all on Regional jets

2 hour and 21 minute train ride to Union Station + walk to blue line, or drive 2 hours 30 minutes to Chicago. Detroit is about 1 hour 50 minutes away, GRR is about 60 minutes away. Once you start rationalizing 60 minutes - you ask why not just drive to ORD/MDW/DTW?

All of that vs. a 8 minute drive to AZO. I do try and fly out of AZO, even for leisure.

This is Concur

Somes it does feel like you are connecting and just hopping on more RJ's and CRJ's. To one of the busiest airport in the world never the less...