Photographers are fascinated by camera gear. You'll hear voices saying: 'cameras don't matter - photographers take images not cameras'. Funny how those same voices go on to talk about camera gear for the next 500 pages of their website.
Recently I sold my Leica M9 and I miss it like an old friend. My ratio decidendi was Leica's announcement of a replacement, the M240. However I've yet to see a decent photo taken with this new CMOS sensor based brick of painted brass, so I'm in Leica limbo. The M9-based Monochrom looks great, but while it appeals it's insanely expensive.
The other reason I sold my M9 was noise. I made a few long exposures up at Eagle Brae, Loch Ness, with the Leica M9 and Nikon D800e. The Nikon image of the Milky Way was outstanding, the Leica image was a mess. It was clear the Leica was hugely inferior so why do I miss it?
The reason I miss my M9 is it's modus operandi - it's simplicity. Despite it's noise, poor battery, slow data transfer, old technology ad infinitum, when I peruse my favourite images - especially portraits - most have been created with the Leica M9. Most likely this is due to the wonderful lenses like the 90mm Summicron and 50mm Noctilux. These lenses are fabulous and simply do not work as well on other cameras like the Sony A7r, so I guess I'll have to wait until Leica make a digital camera as good as their lenses.