If you can live with the cost then the M9 is the right camera for you. Instant output, portability, lens use and enjoyment of usage are all covered.
I don't mind carrying the D700 even with the pro zooms I have but that's me.
I sold the M9 because it just didn't do it for me and bought another MP instead. Each to their own as they say but I like Leica's for film and Nikon's for digital.
I would buy another M9 but only when the price hits $2500 and sooner or later it will, that's the nature of digital. As for waiting for the M10, one can sit and wait forever and there will always be the next best thing but in the meantime you are missing photos.
The M9 is a great camera when it works as intended and I don't want to get into reliability issues but it's always in the background so one has to calculate into the equation the cost of repair if it needs them. I'd always want a solid warranty with a Leica digital.