Like BLS with his RC45, my current 2001 ZRX1200 has that something extra. A “few” mods later, it’s dropped 40 lbs from stock (just under 500 lbs, half tank of gas). Doesn’t sound as good with “just over 500 lbs and a full tank”, lol. Re-valved compresssion/rebound and custom springs in the stock KYB rear shocks by Daugherty Motorsports, a little fiddling with the front forks along with ZZR1200 cams, ZZR1200 carbs and JE stock bore 12.5:1 pistons has it singing a fun tune both in a straight line and for what I am capable of, in the corners as well.
However, if I am being totally honest with respect to the fun factor of being able to use all power and most of the handling a bike is capable of, a Nighthawk 550, Yamaha Vison 550 and Honda CX500 were the most fun for a ride on any afternoon.
Over the past 10 years each one of those has been in the garage as a fixer up project and then turned around and sold to someone looking to “get into riding” and they are the perfect bikes. To my mind, mid-displacement bikes of the early-mid 1980’s can’t be beat. The newer ones have little soul, IMO.
I suspect the appeal of the RC45 besides being rare, is the manageable power and impeccable handling that makes it feel “easy”.