Not quite the comparison you’re looking for… I owned a real nice J-3 Cub for 23 years. Flew it 1100 hours. I agonized about selling it when I bought my 12 eighteen months ago. Everyone clamors for a Cub - thought I’d miss it. One flight in the 12 and I never looked back. The 12 is a beautiful airplane anyway you want to measure it.
I used to fly the Cub with the door open. The 12 gets plenty of ventilation in flight and excellent on the ground with the canopy ajar. You’ll want a retractable sun shade. Visibility in the 12 is eye-popping, I think even better than the Cub.
You’ll love the way the airplane flies. Control harmony is perfect. I still have the RV grin with almost 200 hours accumulated in just 18 months and I don’t fly in the winter.
Cruise is on par with C-172 or Cherokee and the 12 will easily out-climb either. If you want X-country flying then get the two-axis autopilot and sit back and go…
P/ASEL 1970 Sport Pilot since '04
80 hrs Flying Aeronca Chief 11AC
1130 hrs Flying 46 Piper J-3 Cub
RV-12 E-LSA #120058 AWC 7/12 Bought Flying 10/15 with 48TT - Hobbs now 317
LSRM-A Certificate 2016