Welcome!

While none of the US big 3 FF programs are great, as far as return on $ spent, DL has been the worst for awhile now.

Rack up some AA LPs and then take an Etihad first class trip to Thailand or something for 90,000 LPs, and you'll see what you've been missing. I don't think DL has any sweet spot redemptions quite like that.

Caveat -- others on this sub-forum will differ in preferences, but I stick with AA for 3 reasons mainly: 1) as an EP I get a lot of upgrades, and Admirals Clubs aren't **too** crowded; 2) internationally, AA biz is actually not too bad and their lounges and partner lounges are some of the best; 3) I like taking some pretty aspirational and epic reward trips to international destinations (already been to Fiji and Tokyo this year in J, going to Bangkok in December), and AA's partners and partner-award chart still make this **relatively** easy compared to UA and DL (you can def find Int'l 1st and Biz availability on JL, Fiji, EY, QR, etc. ***relatively** frequently if you keep your nose to the ground).