Another newbie oil question

I use 50% ATF, and 50% dino 75W90 full time year 'round.
I highly recommend against a FULL synthetic. I modded my cones and rings to use that stuff, cuz I really wanted to use it. After three times in and out, I quit trying and went back to my tried and true 50/50 and the trans shifted like lightening.
But there are guys here on FABO, that are using a Redline-brand synthetic manual-trans specific oil, and are having good results; go figure.
I forget what year it was but there was a time when 100% ATF was recommended, and mine works really well with that. I only use the gear-oil to protect the cluster pin which, with over 400hp going into the trans at times, is very heavily loaded. At last inspection, the pin was in very good condition.