I'm an FO at Avantair and just went through my recurrent/"upgrade." I too expected to actually upgrade when I went through this, but I can't blame the company for the economic downturn. It sounds like the OP's biggest issue was the low FO pay. I'm not a big fan of it either, but have personally heard from upper level management that it is one issue that is on the fast track to be addressed. They're open with their policies, and have always treated me fairly.
The OP knew the pay scale when he signed on... It hasn't changed in a couple of years, it's not like the rug was yanked from underneath him or they kept it a secret until the time came. As far as upgrades slowing, well again, at least we're not furloughing!
I'm reminded of the disclaimers on weight loss and investment infomercials that say "Results not typical" or "Previous trends do not indicate future performance." Upgrades in under one year can't continue indefinitely at any company, I don't care how good or bad the economy is.
I hope his new "5-on 25-off" job is as good as it sounds. I've flown Citations in the corporate world (and made a lot more money than I'm making now), but personally could not stand the lack of a hard schedule. Some months, I had close to 25 "off," but those were days I couldn't make plans, go out of town, or have a drink at a backyard BBQ... My phone might ring and I'd be "on" again.
I'm not going to make sweeping statements about what percentage of people are happy here, but if it was as bad as he made it sound, I think we'd have a lot more attrition (meaning a lot more room for upgrades) than we have now. Just my $.02.