Unless your company pays for business or first, I would stay with AA and enjoy the exp perks!
I was exp for 8 years before my company cut back travel. My employer does not pay for business or first class. The upgrades were very nice! As a plt, I never get upgraded anymore out of DFW. I have over 30 - 500 mile upgrades in my account, request upgrades all the time, but never get upgraded.
Enjoy it while you can!