I think within the 28-32% ranges it's more the advantage of increased bottom time rather than limiting post-dive fatigue. On week long liveaboards with multiple dives /day diving I frequently use Nitrox and run Nitrox settings on my dive computer. The increase in bottom time is significant at certain depths and well worth it. On the other hand, my brother uses Nitrox but likes to run on air table settings just for added safety and he frequently ends up putting his computer into a few extra minutes of deco diving similar profiles... which makes me wonder why he bothers with the extra precaution if he's going into deco most of the time
As to how I feel after several dives on Nitrox versus Air.... I can't really tell the difference but as was noted in the Alert Diver article referenced earlier - the placebo affect is a powerful thing and if it makes you "feel better" then that's a good enough reason to use it.
As to how I feel after several dives on Nitrox versus Air.... I can't really tell the difference but as was noted in the Alert Diver article referenced earlier - the placebo affect is a powerful thing and if it makes you "feel better" then that's a good enough reason to use it.