I have an M9 and like the images I can make with it. I had an M8 and found the color response/IRR filter issue annoying. Never had a problem with the RF or shutter replacement. Going back to the M8 files now, I find they are pleasant. However, the M9 was an upgrade on all fronts, though, no question. But I think Peter has the right idea: If even only for the sensor corrosion issue. You are buying a pig in a poke, even with a recent sensor replacement, because the replacement is the same product that just failed. If you are going to spend this much money, spend it once and do it right. Buy your way around/out of the CCD issue and go straight to CMOS.
I'll just pause and say that the old argument for the price of a Leica was that you'd buy the camera once and use it for decades and that it was therefore worth two or three month's salary. The camera industry has taken this argument away though. I have used the M9 since it came out, replaced my sensor once, and am basically just holding my breath on how long the replacement will last. If I had the scratch, I'd go straight for a CMOS sensor and never look back. This is not -- you understand -- because of any difference in image quality. It is just about being able to rely on your MASSIVE investment for the long run.
Also BTW: I have no idea why a shutter is necessary any more - go M10?