Just to get it right, the CLE and the CL are both just as reliable. The naysayers about the CL compare it to a Leica M that is a hammer compared to almost all rangefinders while the CLE gets compared to the more mainstream bodies. Very unfair to the CL. Leica lovers I think have it in for the CL because it killed the M sales while it was out, or so they say. The realty was Leica sales were tanking before the CL came out and the CL's profits saved the company from extinction but, as it was an orphan the M supporters eventually got it discontinued.
The CL like any camera of that time is due for a cla and maintenance to be reliable, even the M series of this age require it. I had my CL serviced more than a decade ago and have heavily used it since with no problems, including the metering circuit. The key is to use a good tech like with any camera. Mine was done by Leica USA.
The CLE seems near end of life as the parts to keep them running are drying up or have dried up while the CL is still supported by Leica for repairs as well as persons like Sherry. Even the photocell is available if needed. During the life of the camera, there were numerous improvements and while generally the later s/n s are the ones to go for, Leica USA installed them as silent recalls when servicing the CL according to them when mine was done and I understand Sherry likewise can install the changes.
The CL is all mechanical using the battery only for the meter. It has no automation and that may be the limiting factor for many who prefer the CLE for that reason. As for lenses, the CL can use the 28, 35, 40, 50 and 90mm with no viewfinder though there are no dedicated framelines for the 28 and 35; they use the outer edge of the 40mm lines and the full viewfinder.