I installed R80.20 and R80.30 on 12x00 appliances w/ VSX, in totally separate environments and have had production issues with both releases.
I don't want to comment on them out of customer confidentiality and there are still open TAC cases which need to reach a conclusion, but they kept me quite busy. I've installed R80.10/20/30 extensively in other environments (Open servers, 5x00, 15x00, 23x00 systems) and these specific issues only occured with the 12000 series. So if I were you and everything works fine, I'd wait a bit for a few more HF or lifecycle the systems.