Hello - new member! I own a '78 R100RS and used to own a '80 R65. The reality for me is that the 'little' R65 can do pretty much everything that the RS can - except cruise at 160 km/h. Or maybe carry a heavy pillion passenger. The R65 is probably more comfortable, easier to maintain (fuses, old filter not hiden behind fairing pieces) and quicker handling. The R100RS is more stable, more powerful but coarser due the larger piston mass), and prettier. Not sure what the maintenance issues with the rear disc are -- never a problem -- but I accept there's more feel with the rear drum. In the real world (speed limits, etc.) the R65 is a very underrated machine. Mine was probably the best bike I've ever owned in terms of actual riding, and I'd like to get another one -- though I wouldn't sell my RS to make way for it...