The M9 with its CCD sensor is, just like the previous model, the M8, an almost forgotten camera. This is different with older film-loading Leica cameras: the M3 and M4 and M6 are still actual models and share that unique Leica myth. The M9 and by implication the Monochrome has currently a rather tarnished reputation. The problems with the coverglass are not universal, but sufficiently common to generate some unpleasant feelings. This is almost a replica of the IR problems that plagued the M8.
The M9 was at its introduction in late-2009 greeted by all Leica fans and many others with enthusiasm because it was the first digital Leica camera with a sensor that has the same dimensions as a classical 35 mm negative. The name "full frame sensor" is often used as a characteristic, but without specific dimensions the word is empty. Imagine that one would say that a Hasselblad had a full frame sensor, which is true, but meaningless.