The Genesis isn't exactly a "classic" model, but I'll take a stab at the question. You are referring to the Chip Hyde model, aren't you?

If it was my airplane (and I had the spare cash [:@]) I would go electric. Though I haven't flown many electrics, I feel that I can get more precise, responsive, and even throttle control with them. The 'spool up' time with an electric motor is virtually nil, and torque is even throughout. The operating weight of the aircraft also stays consistent throughout the flight, so the airplane handles precisely the same no matter how long you've been flying. Longevity is slightly increased because of the reduced vibration from the electric motor.

Just my .02.