i suspect that your frustration may partially be that 1/12 is very tuning/driving intesive. the 'latest' hot tip may not be required to win, but it may be confusing to wade thru what is really needed vs what is good enough with just the right tuning and driving.
anyways, what i wanted to mention is that a few weeks ago somebody talked me into trying their car. it was a RC18R, which until i tried it was unimpressed. well i drove it for 10 laps and went and bought one on the spot.
you just need to stay in the 'stock' class (or next closest thing). these cars are a kick and provide close racing and high number of grins per lap. now if you start mod'ing the thing i believe the fun factor may drop (to each his own).
anyways, bottom line is everybody has their own idea of what is 'fun'. if you want minimum 'hop-up of the week' syndrome and minimum tuning/wrenching, then try a mini class with stock chassis.