not much difference in weight between an m and a cl? Huh?

My CL is my standard traveling camera for that very reason -- smaller, lighter, quicker to use, dead-on metering, spot metering makes it very versatile, and it uses my 16mm Voigtlander and 25mm Canon lenses very neatly as well. The only camera i've found as good for travel is an Olympus XA, so usually I carry both.

The Rollei 35 is fun but, lacking a rangefinder, is hard in poor light and, frankly, the square shape makes a painful bulge in my pocket while the XA is rounded nicely.

The CL has one huge advantage over the M-series -- being small and black it is less visible and, frankly, doesn't make people think you're really seriously taking pictures, so it is very good as a candid camera.