Owner of the Pro M. Love it, use it for CAD, PS, Illy, SketchUp. Magic Trackpad 2 with my left hand for zooming/panning/gestures and Pro M with my right hand for drafting/drawing/selection.
I use mine tethered. If you opt for wireless operation absolutely add a USB BT 4+EDR dongle (mine is made by StarTech) as Apple abandoned EDR years ago. Wacom used to include an EDR-capable BT module with the 5's Wireless Kit, but wireless is built in to the new Pro models but the dongle was cut from being included. The Pro M is EDR-capable - EDR enables wireless parity with wired performance, trust me on this. My StarTech dongle is Class 1 as I need to connect to a couple of far off peripherals, Class 2 should do nicely...
The new stylus is so nice to use. Touch doesn't suck. The main bit to love is the reduced footprint - same active area, around 70% of the footprint for the M model.
One nit to pick. I frickin' hate the additional utilities installed by the installer - with one key exception. If you opt for the Pro - the installed app named "Wacom Desktop Center" also enables FW updates for both the stylus and the tablet's built-in BT module, with several updates issued since the Pro models went on sale with the latest updates coming out just a few weeks ago...
Regarding the new Cintiq tablets, I get it - I've wanted a Wacom Cintiq Pro 24 but they're still not in stock. FWIW, check out Wacom's store for refurbished products - I've bought a few for my company, they've been flawless. I use my Pro M with an iMP at my home office and a new model 15" rMBP when I'm on the road.