Hi Todd -- You might also consider the Voigtlander Bessa-R2, similar feature-wise to the M6. It's a good camera of the same size with an excellent bright range/viewfinder.
I have a Bessa-T, a CLE, and an M2 and like them all. But I admit to favoring the CLE for two reasons... First, the AE makes it fast in action. Many have wished for manual metering, but it can be done by metering in Auto and switching to Manual. Second, the CLE is small and inconspicuous, resembling any number of compact leaf-shutter RFs.
I've had my CLE since new in 1982. The only maintenance issue has been a metering problem solved by cleaning the internal electrical contacts.
While I do wish the CLE had AE-Lock, I appreciate that it has AE... which the Bessa and M2 do not.
I have a 90 Tele-Elmarit for the M2, which of course works on the CLE. Except that the CLE's viewfinder magnification is lower for the 28mm framelines, making the 90mm frames inconveniently small. This would be true also for an M-body with .58 viewfinder, I expect.
I have used the 90mm on the Bessa-T, which needs an external viewfinder. Good match! The RF is accurate, and the external finder is big, bright, and 1:1. Very nice, and the metering diodes on the back of the body are visible in peripheral vision while the eye is to the finder... or even at waist level.
Good luck in shopping!