I have a suunto zoop novo as my backup computer, which is RGBM and famously conservative. I have my peregrine adjusted to GFHi = 75% and it is actually _more_ conservative than the Suunto most of the time. For liveaboard diving, where you do lots of dives but limited to 1h, that has not been an issue for me, although I tend to be a bit more conservative about depth than some people.
If you want to dive in deeper to the dispute, RGBM is based on "bubble models" which are somewhat discredited among decompression researchers. Or at least that's the consensus around here.