Based in DEN. My work travel has increased year over year, so I started as 1P for 3 years in a row, then hit 1K last year and this year, thanks to tons of international travel in J, I am GS. We have a corporate deal with UA, so we have to use them unless price difference is noticeable.
I rarely travel domestically for business and if I do it's to a mainline destination like IAD or SFO or LAX. Personal travel also seems to route through mainline (sometimes with an RJ extension, like ORD-MBS). I have weathered 2.5 hrs on a CRJ-200 to MKE for personal travel, which is awful. I also occasional travel internationally for personal travel, all in cheapest-available Y. With a spouse and 2 kids, CPUs don't happen on personal travel, although I have used GPUs and RPUs at year end for runs to DCA/IAD when they would otherwise expire without use.
WN took share from F9 and UA, and when I have flown them I have been suitably impressed (classic case of delivering exactly what they promise), but WN gets me nothing for international travel so I load all travel (including personal) with UA to accrue, and then take advantage of, status benefits.
UA ain't great, but IME most airlines are not good to travel on, especially when IRROPS arise, so to me status takes care of those issues.