I would answer the question first : lenses.
Long ago I was wondering what could be that little plus Leica could have that a Japanese brand was lacking for the enormous price difference.
Until the Nikon FA hit the shelves, the F…k All we used to call it, because it was really flawed ! I already had a very bad experience with the EL, destroying ten rolls of Kodachrome.
From that point on I knew the trend would be going all electronic. So I stepped into Leica.
Then I discovered deep detailed shadows in my slides, sharpness right into the corners, unctuous greys in the prints…. and as the equipment can last a life or two, I switched to Leica entirely.
Then digital arised and there Leica was lost. They shine in optical and micromechanical, they are specialists, but electronics is a complete different world, far less demanding with programmed obsolescence policy. This is a consumer industry, high turnover and low reliability. Two opposite worlds that tatooed Leica cannot grasp, they still identify Leica with abosolute quality, they throw 7000 $ into a piece of electronic that Leica doesn’t produce, believing they are buying the long famous high quality product.
The lenses remain what they have always been (at least until Leica get into AF) excellent, but the cameras have nothing to see with what they used to be, it is electronics into a Leica box, their value should be around 800, period.
Now if the question was about Leica film M cameras vs lenses, my answer wouldn’t be so straight. Range finder shines for candid shoots, but I manage as well with reflex. Where RF is best suited for is low light situations…..if you have a Leica lens together with. So I would keep my first answer : lenses.
Going a bit further, as I said earlier, the day Leica get into AF, then just forget about the brand altogether. They are thirty years late on this, they will have to switch to plastic components and again electronic and they will ask you 4000 for a lens…. then the answer to the question would be : neither.