Most COS FO transfers are still in IOE. It’s not a big base, but there’s a lot of movement at the junior end as folks move through on their way to Denver or further west, so reserve isn’t long. CA is another story though. Not super senior at the low end, but not a ton of movement either. No stand ups in COS, which could be a plus or a minus, depending on you.

If career progression is all you care about, then go to the most junior base for captains. But life is a journey, not a destination. COS is a great place to live and I really enjoy the job here. If you want to actually enjoy your time at the regionals, you should consider COS or Denver.