I've been on 8.1.9 on 3020s, vm-300s, 820s, 850s, 220s with no issues. I believe that is the recommended support version.
Probably want to install the latest 8.0 version, reboot, download 8.1, download 8.1.9, install 8.1.9, reboot.
The upgrade path that @craigomatic already mentioned would be what I would follow. Keep an eye out for when 8.1.9-h4 actually hits recommended status so you're covered for the three vulnerabilities they announced Wednesday, by the time you upgrade 8.1.9-h4 might have actually had enough time to mature to reach a recommended status.
Update: I'm starting to get some weird behavior on my 800 series running 8.1.9, like management goes to 100% for an extended period of time, making the device unmanageable. Did I read about a memory leak? These have all been running > 30 days. I'm upgrading to 8.1.9-h4 immediately.
I didn't see anything about a memory leak in the list of addressed issues for 8.1.9-h4 in the release notes. There were fixes for memory or buffer leaks for previous versions of 8.1 though.
Click Accept as Solution to acknowledge that the answer to your question has been provided.
The button appears next to the replies on topics you’ve started. The member who gave the solution and all future visitors to this topic will appreciate it!
These simple actions take just seconds of your time, but go a long way in showing appreciation for community members and the LIVEcommunity as a whole!
The LIVEcommunity thanks you for your participation!