I was wondering, if after experiencing 100m on air do you feel less impaired at say 60m than you did when you began doing these deep air dives?
Short answer is no. It varies from day to day, and if I take a break from diving whatever "acclimatization" - for wont of a better word - I did have wears off.
Having said that, I can now do a 45-55m dive as the first one of a trip & feel ok - whereas my first ever 43m dive at Fish Bowl I was very narced (euphoric, paranoid, impaired mental function).
Do you feel you have built up a tolerance to deep air or just learned to deal with the impairment?
As above, repetitive deep diving definitely has some effect, particularly in the short term - but I believe it's more learning to be aware of/dealing with impairment than reducing it, and I don't think there's much you can do about the cognitive impairment. You can certainly reduce some of the symptoms though which is helpful IMO.
OTOH some people just seem to have low tolerances, I have seen people have massive memory loss at 50 & go totally unresponsive at 65.