Looking on the travel planner, there are 9 flights a day between DFW-PHL. All of them are in an airbus (for now), so you'd have the benefit of two jumpseats.

I can't speak from personal experience, as I don't commute myself. However, I truly believe you should choose a regional based largely off of how to get to your end goal fastest. If you want to be at AA in ~5 years, Piedmont is far and away your best option. Commuting to PHL will be kind of a pain in the short term, but if it gets you home based in DFW at AA, you'll have it made. I'm sure you've considered all this, but it pains me to see people go to a crappy regional so they have an easy commute for the short term. I play the long game