Sierra on a late 2009 iMac?

[macnicol]

Running El Cap now, any suggestions or cautions about upgrading to Sierra or High Sierra? Yes, I have several bootable backups available.

 

[jbarley]

Running El Cap now, any suggestions or cautions about upgrading to Sierra or High Sierra? Yes, I have several bootable backups available.

Can we assume that you are familiar with these two associated lengthy threads?
https://forums.macrumors.com/threads/macos-10-12-sierra-unsupported-macs-thread.1977128/
https://forums.macrumors.com/threads/macos-high-sierra-10-13-unsupported-macs-thread.2048478/
If so, then I'd say go for it...