I went the opposite way, starting with a Contax IIa, then an S2, then a Leica M4-P. Got the Contax because it was less expensive than any Leica at the time, maybe even more so today. There were a couple of things I didn't care for on it, mostly the smallish viewfinder. So, when I decided to change systems TomA talked me through the process, and I settled on an S2. Very enjoyable to use, and the lenses are superb, even the smaller aperture ones. Still, the reason behind getting the M4-P was all the available frame lines instead of having to rely on external viewfinders. But the S2 is the one I like the most. I can't really quantify why that is, it just speaks to me in a way no other rangefinder camera does. Using the bottom half of the eveready case softens the handling a bit and adds a touch of class.
I say, if you have the opportunity, handle the camera first to see if it feels right to you. Then make up your mind on whether or not to get it. If you do purchase it, and it is in good condition then you should be very satisfied with it.
PF