I was in the same boat 6 years ago. At the time, SWA would get me into Denver within a month or two. My neighbor had been commuting to Denver for United for years and said he would “never” upgrade to Denver captain at United. Flash forward to 2022 and I can probably upgrade next year in Denver (in my 7th year at SWA). Meanwhile, United friends hired at the same time as me who were looking at 2-3 years commuting to Denver and 15+ years for an upgrade are now all Denver captains for a couple years and/or working in the training center.

Who knows what happens in the next 5 years, but I would take the fleet diversity and training center options at United over SWA if I had to do it again.