It seems to me the fuss about rangefinders runs on two parallel courses. Leica and similarly high-priced camera systems or fixed-lens rangefinder/viewfinder cameras which have always been intended as easy-to-use, carry around cameras. I find it amusing that so many people compare the likes of the A5 to their Nikon slr or Leica rangefinders.
I have an A5 which takes great photos, always well exposed - except for those occasions when the mental calculator lets me down or I become overly ambitious. Mine has the 45mm f2.8 lens which gives good colour, good contrast and sharp photos. It has a four element lens and I believe there was a 6 element f2. I've never enlarged beyond 10"x8" but then, if that is your intention, you won't bother with a camera like the A5. It has weight and bulk compared to the more pocketable rangefinders such as the Canonets, etc., making the handling closer to that of an slr. Do keep in mind it is close to 50 years old. The 1 second speed on mine is more like half a second while the half is more like a quarter. Irrelevant really, as few people using this type of camera would ever have need of those slow speeds. The rest of the speeds seem fairly accurate.
If the learning you have in mind involves being in full control of the process of picture-taking, then obviously a meter-less camera is the place to start. Don't bother with a hand-held meter, it gets in the way. Use the sunny 16 rule and learn how to bend it to achieve the results you want. Modern print film has such a wide exposure latitude, you can get away with small errors in judgement (Of course, its the errors which help us to learn). With experience you'll find you don't have to think much at all. Just look around, feel the light, set an exposure and shoot.
Of course, it will never replace a modern slr, film or d*****l, but can be a lot of fun on those occasions when you want to keep it simple.