I own three different systems, Nikon (manual and AF), Canon FD and Yashica, and couldn't care less which I'm using. Each delivers sharp images within the limits of a 35mm negative or transparency. My preference is for reasonably compact, fairly light cameras, if only for the fact I'm more likely to carry one with me, but hauling a metal bodied manual camera can be fun, so long as I wasn't expected to do it habitually.
Perhaps it comes down to whether you believe photography is something that fits into your life, or life has to revolve round photography? My best shots often come while doing something else, so some photographic compromises have to be made regarding the range of lenses carried and weight of camera bodies. I rarely feel under-gunned with an SLR and a 50mm 1.4 lens, but a 24mm acts as a comfort blanket in another pocket. For the times even an SLR is too much, my Olympus Mju II is as minimal as a 35mm camera can expect to be.
My fave SLR camera would have the optics of Contax, the build quality of a mechanical Nikon and the size of a Pentax ME with pancake lens.