While I am based in PHX, the actual routes that I fly tend to favor DL or UA, plus with DL having a better in-flight product and UA now catching up with United Next, I think I would prefer my loyalty with airlines with better in-flight products. Plus DL and UA aren't all that small out of PHX, being 3rd and 4th, respectively, in number of flights. I have the Delta SkyMiles Platinum Amex and I was just approved for the United Quest Visa Signature. What sold me on these cards were the companion certificate and the $125 flight credit, respectively. The companion certificate is useful for taking a family member on a summer vacation (I am going to visit my cousin in Boston this year with my mom), while the flight credit is useful for holiday vacations mainly to BQN which UA flies to.

So, should I drop my Barclays AAdvantage Aviator Red card? I would prefer not to pay the $99 annual fee. I understand that downgrading to a $0 annual fee card with Barclay's isn't easy, although it would be great if I can downgrade my Aviator Red to the standard Aviator (aka Aviator White). I have previously looked at award availability to BQN with AAdvantage, and last time I looked they didn't offer anything at all via B6 from PHX (I presume PHX-BQN isn't a bookable pair on AA despite the B6 codeshare). For BQN I think UA will likely be more useful for me, while for domestic I think DL is best for the companion certificates plus I frequently fly to ORF, an airport which DL is strong. I can still earn AAdvantage miles via AAdvantage Dining and AAdvantage eShopping to keep my account active and just to have a backup FF program. My dad has the Citi AAdvantage card anyway.