Installed 17.10 succesfully, just about everything works, including Ubuntu Mate desktop important feature, the best HiDpi scaling in Linux. The development team has done a great job!
Small thing: when booting, the ethernet notification keeps coming up, but it can be turned off.
One ugly thing, that already came up on this forum:
UbuntuMate has annoying Firefox packaging, forces the home page to search engine with Ubuntu Mate logo.
become root (su or sudo)
cd /usr/lib/firefox/defaults/pref
edit file all-ubuntumate.js
with editor, comment out both lines (add # in front of the line)
restart firefox, setup home page to your liking …
This is just a hack to disable this javascrip. It is very unthoughtful of somebody having put it in there. There could be somebody somewhere working in an office where the requirement is to use company home page, Quick Books as home page, etc.
Yes, it's a bug in Firefox (and part workaround on Ubuntu MATE's side), the bug report is here.
It seems this upstream bug report seems likely the cluprit though.
An alternate is to just delete these files:
sudo rm /usr/lib/firefox/defaults/pref/all-ubuntumate.js
sudo rm /usr/lib/firefox/ubuntumate.cfg
HiDPI scaling? Not work out of the box and I didn’t found any settings related to that…
Could you give few tips? 
Control Center > Appearance > Fonts > Details > Resolution | | dot per inch
For a 3840x2160 screen, try setting this to i.e. 135 or 140, fonts, windows, window decorations, menus scale really well.
Hey,
Perkele thank you! I will try that out tonight. I have Dell 15" laptop with 3840x2160 resolution so it was super tiny. I dropped my resolution down to 1920x1080 so it was usable, but not so crispy sharp anymore.
Do you have found any problems with that font scaling methods? If majority of MATE menus, apps and such is OK. I know that there is some work still to do to get all apps to work in HiDPI (example Steam, Gimp icons…)
No, no problems at all. There are a few programs that use fixed font size, like Pluma, where the fixed font size may need to be adjusted, but most applications are perfect without any tinkering. Also, I adjusted window titles size up one point afterwards.
This method is also much better than that of Gnome3 or Cinnamon, where the HiDPI has only two settings, normal or large ( tiny or huge). This way you can adjust for your 15 inch laptop or my 27 inch desktop and everybody’s personal preference.