Okay, a new variable in the discussion; just keep the Rolleiflex. You'll play a lot of games before getting anything near the quality potential of it. I have a 3.5T and it can go head to head with my Leica.
As for the Leica M series vs the CL, a M body that is in about the same shape as a CL is more expensive and the 40mm Summicron-C that was for the CL is a bargain as far as Leiica glass goes and is considered by many owners as one of the better Leica lenses. I concur. I prefer the CL to the M bodies as it is smaller, close to the Barnack LTM and the meter in it is superior to the M6 though like many cameras of its age, it may need some work. I had mine redone about 1990 and the cost was not as much as some think when saying it is an expensive proposition and the meter has been working perfectly since and is dead on accurate. It is a spot meter so unique as most in-camera meters are averaging meters.