As a former CoreOS (now Red Hat) employee, I'm glad to hear of your success with the product and it's awesome to see that scale giving you time back in your day to concentrate on the big picture.
Not at all happy with things right now. You guys abruptly killed CoreOS which was great and left us to fend for ourselves. Fedora CoreOS doesn’t cut it and we don’t want open shift. We will need to move to either bottle-rocket or flatcar. A team member evaluated both and we leaning towards b-rocket since flatcar has a higher risk of dying by running out of funding during COVID (seen this movie before with CoreOS). Amazon’s customer support team is also a lot better.
1. update wasn't possible - that basically means that customers can't count on you
2. some decisions favored OpenShift instead of being general purpose
3. you rebuild the whole stack?! from scratch?!
4. the documentation is twice as bad as from CoreOS (which was already pretty bad)
5. the market now has more to offer, way better solutions. Fedora CoreOS is basically just a rebuild CoreOS that brings nothing new to the table and shaken up all customers. if I need to reinstall my nodes anyway I can evaluate k3os, bottlerocket, opensuse microos, rancher, whatever which didn't sleeped while you guys did rebuild your stuff.