I'm glad the OP had a favorable impression of CO. In my two years of eliteness, I've never regretted having chosen CO, for the reasons you mentioned - decent service on the ground and in the air, courtesy from employees, etc. To that, I would add that the experience is predictable - the product is basically the same across the route map and across the fleet. They're pretty good, though of course not perfect, at handling upgrades, irrops, and other aspects of the flying experience. Some have said the OnePass redemption availability isn't the best - I've not had much of a problem. I'm glad, too, that when CO isn't the best price/route/schedule to get me where I need to go, DL and NW are both options. DL has usually been okay, though delays are a problem on ASA. I will fly NW later this month for the first time since toddlerhood.

Welcome to CO!