It's hard to gauge experiences from APC. People who like their jobs generally don't say so (not the trendy thing to do here.
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That being said, as a former SkyWest guy, I enjoyed my time there. I also enjoyed my time as an instructor. I definitely had to work my tail off as a CFI to put hours in the logbook, (and food on the table,) but it's a great way to meet people and a great way to learn how to work as a crew.
IMO, you want to pick the regional(s) that have your desired bases and go from there. Where do you to want to live or commute to? If the majors or your ultimate dream job don't call you, then you'll already be set because you'll have great seniority and good QOL. First year pay and seniority sucks, but it does get better.