Compared to the separate lenses, the Q2 is certainly a good deal in Leica's world. Without turning this into a Leica forum, I can confirm that the current digital Leica's still have amazing colors. I was a bit disappointed with the M8, but since the Q, the SL and the M10 they've found their consistency back. What's particularly striking is how easy the raw files are in post. As for the Q2 Monochrome, I've never seen such beautiful and high quality B&W images from a consumer camera.
It's quite a difference. As a basis the Leica Q2 already has a very good 47Mp full-frame sensor paired with one of the best lenses ever made (a 28mm Summilux). By leaving out the color array filter on the sensor and optimizing the sensor lenses for monochrome images, you get an incredibly sharp and contrast rich monochrome image. Without the color array filter you also boost the low light performance and expand the dynamic range of the sensor by approx. 2 stops.
In the meanwhile, I couldn't resist and purchased a Q2 Monochrome. I'm not disappointed. Though my X-Pro produces very nice Acros files, the Q2 Monochrome is a different league (also in price to be fair). I usually shoot monochrome for my personal work, but to be able to shoot at ISO25000 and have files as clean as an X-Pro at ISO1600 is amazing. At normal ISO levels, the level of detail and the tonality of the Q2 files is stunning. Both for the jpegs out-of-camera and the DNG raw files via Capture One.