From a personal perspective - even with 2 hour plus sensible surface intervals - I tend to increase the shallow stops by about a third (usually adding 5 min 6-0m to the profile at / from 6m rather than including it as part of the time at 6m) I also tend to use O2 for about 6min 6-0m (3min at 6m then 3min to the surface) on shallower min deco Nitrox second dives of the day to clean me up a bit. We found this strategy worked very well last week at Scapa.
Diving rich Helium mixes makes a hell of a difference - it was really obvious in the way I felt after a 40m dive on 26% Nitrox on the last day (boat had run out of Helium) Did a conservative sensible profile with a good ascent and still felt way more tired afterwards than I had doing similar dives on 25/25 or 21/35 on previous days. Bloody expensive - but I can't argue that it works
HTH mate