Decent sensitivity for mouse with Ubuntu

Having acceleration/sensitivity set to their slowest/lowest settings in System Settings, for a lot of mouse devices such as the otherwise so excellent Microsoft Bluetooth Notebook Mouse 5000, the sensitivity/moving speed is still far too high.

Here is how to fix that (from Ubuntu 12.04):

First, you will need your mouse ProductName and ID:
$ xinput list

...
 Microsoft Bluetooth Notebook Mouse 5000 id=14 [slave  pointer  (2)]
...


Test a new sensitivity level (14=device id, 1.7=level - higher level lowers sensitivity):

$ xinput set-prop 14 "Device Accel Constant Deceleration" 1.7


Create a new xorg file for the new setting:
$ sudo gedit /usr/share/X11/xorg.conf.d/50-mymouse.conf
Containing the following:

Section "InputClass"
   Identifier      "Microsoft Mouse 5000" # Whatever you want
   MatchProduct    "Microsoft Bluetooth Notebook Mouse 5000" # Product name from xinput list
   Option          "ConstantDeceleration" "1.7" # The same value as xinput
EndSection

Setting now sticks after reboot.