^ This.
When moving from R77.30, I would opt for regular CPUSE, not BLINK. Blink gives you the benefit of getting the latest recommended JHF as part of the process. But considering Blink was introduced with R80.XX, I wouldn't trust it to work when moving from R77.30.
As others have already mentioned, Check Point TAC, Check Point PS, and my local Check Point offices have always told me to upgrade from R77.XX -> R80.40 -> R81.XX. To get the full benefit of R80.40+, you must completely re-install using ISO/USB to get the XFS file system. On R81.20 there is also the 4K disk alignment, this also requires the hard drive to get formated.
This is more important in management installations. I would not move to R81.20 on the management without getting XFS and 4K disk alignment. It's still beneficial to do so on gateways. But it won't matter as much as you don't have nearly the same amount of writing to disk as you have on management installations.
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