Loyalty for me is about lounge access and upgrades. Lounge access would not be enough for me to stay.

No upgrades and I would fly where I get the most. That might even include going with UA/MX for some more Mexican Hat dance trips with side trips to Canada. I might even fly on WestJet! Up until now I have found all sorts of ways to avoid flying other carriers which might have been a bit (or a lot) cheaper, more convenient to fly on my upgradeable AC.