I think you'll always get a biased opinion according to the subforum you post at
but well, I've tried at a shop once an M6 TTL .58x and had a Hexar RF for some time, also shot a couple times with a friend's CLE.
the M6 feels more reliable, if you're used to Leicas you'll be right at home.
the CLE is pretty cool due to its compactness, if you value this it's really good. the 28mm frame takes up the entire viewfinder area.
the Hexar RF has a viewfinder that is pretty much as good as the M6's, and has a higher accuracy due to the slightly higher magnification. sweet bonuses are the automatic advance, aperture priority, 1/4000, being able to rewind mid roll.. the downside is that it's a bit noisier than the other 2 due to the motor advance. still, my vote goes for it
but be aware that fixing a broken Hexar RF might be a hassle, it's easier to find someone that will repair a Leica. then again it's always a bet whether the camera will or will not show problems.. be them from any brand.