Regarding M9 vs. M240... the endless debate.
IMO, choosing one over the other for image quality is splitting hairs. One can be processed to look like the other, if needed, though the wider dynamic range of the M240 is a benefit in certain situations (and the root cause, IMO, for its considerably different SOOC look compared to the M9).
The M9 is a more focused camera - it's strictly an optical rangefinder style of shooting. No live view, no EVF. No easily controlled manner by which to use non rangefinder coupled lenses. The M240 to me is more multifunctional - along the lines of an a7 in terms of lens adaptability (and may be a reason some consider it a watering down of the Leica rangefinder experience). You can use R mount, or practically anything else other than those that require electronic control interfaces. It's a reason why, for me, the a7 series is difficult to justify and much more of a compromise. I can use the excellent M system lenses natively on it (which is a high priority for me) without edge smearing and also adapt other lenses, if I wanted to, the primary reason I'd get an a7 series camera, since I'm happy with my Canon gear for any serious AF/action type work.
IMO, the M240 also offers a range of UI and usage refinements over the M9, but the relevance of these points is subjective. Covering events, the responsiveness improvements of the M240 make it a vastly different camera in use, and is important for me. Using the M9 alongside the 240 and a 1DX, it feels like shooting with molasses. Yet, recently when the M240 was at Leica for a quick rangefinder calibration (due to my momentarily careless misuse of it - not to imply there is a general RF calibration problem with it), I used the M9 for a day on the streets of NYC and enjoyed it.
On its own, the M9 is definitely enjoyable, and that is how I guess most use it. For ~$3000, you get a lot of camera, and compared to the M240, save over $4000, which will go a long way towards any out of pocket repair costs.