I think this concern of some people is that the RGBM is too conservative and there isn't a way to make it less so. DSAT, on the other hand, tends to be more liberal and you can "dial it back" if you want to make it more conservative. That said, I have dived both the Mares RGBM and "wide open" DSAT together under a variety of conditions and on certain repetitive dives, the Mares is slightly limiting relative to DSAT, but not enough (for me at least) to be annoying (and maybe that minor limiting is good?). If you are diving as you say, I don't think you will notice and even if you were more aggressive, I doubt it would be a problem. Again, I think this is probably a selection factor, but not a major one if it were my decision. If I liked the Mares better for other reasons, I would go with that. Likewise, the Oceanic.