I remember using nitro once back in the mid 70's but that was just for a K&B 15 in a CL rat race competition (which we won and it was a state championship too
). Other than that I've never used it because I've never found it to be necessary. The method of supporting the crankshaft (plain bearing or ball raced) makes no difference as to how the engine will respond to no nitro. Neither does compression ratio make an engine harder or easier to tune. All a higher compression does is allow the methanol to burn more efficiently so giving more power. Maybe it's because zero nitro is normal for me but I've never found any engine hard to tune, certainly not this mythical "one click goes too lean and one click too rich" business. Obviously the needle is more sensitive but if you take off your boxing gloves
they're surprisingly easy to tune.