After an extended PM conversation with icurhere2 (who has provided valuable insight in regards to the AA vs DL comparison, as well as the respective airlines' flights in/out of BNA), I believe I have concluded to proceed with Delta.

The reasoning behind this decision is two-fold:

• Status match: As most of you are aware, AA is unwilling to match elite status of a competitor airline (in my case, US Silver). While FO with DL will not provide much assistance in terms of upgrades, the fact that I am guaranteed FO through 2/11 is extremely beneficial. Sure, I could pay $80 (or $150 if attempting the PLAT challenge) and fulfill the requirements for AA Gold, but then again, for me to offer my business on a consistent basis to an airline at a time when the entire industry is struggling, the least I expect is to receive some immediate benefit in return; Quid pro Quo.
• Domestic outreach: As some of the PPs pointed out, AA’s domestic outreach leaves a bit to be desired in regards to mid- to small-sized airports. In the pasy year, I have been required to travel to Concord, NH (via MHT) for two full months. As AAdvantage elite, I would either have had to fly to LGA or ORD and finish the trip on UA or US OR I would have just decided to make the entire trip on US/DL/UA/etc. This restriction on domestic outreach is a much larger negative for AA than any of the other cons I listed for DL, IMO. Also, the addition of MEM and DTW will provide improved routing options, as previously mentioned.

As a final question, are there any of you that strongly disagree with my final verdict? If so, could you please explain your reasoning?

Thank you again to all of you who have contributed!