My first UT device is a Nexus 7 2013 which I bought specifically for installing UT.
I bought a bq E5 HD Ubuntu Edition and had it brought from Europe to the Philippines through a friend.
I bought a second hand Nexus 5 which has Android, Sailfish OS, UTs (depending on my mood) made possible with multirom.
I developed and published 3 great (self-recognition) apps in the OpenStore named Talaan, Tagatuos, Palitan and Pesbuk.
I mainly develop my apps directly on my Nexus 5 via X-Forwarding using Qt Creator/Geany and clickable.
I've recently been involved in OS bug fixing (one-liners :D) and some OSK enhancements such as the theme support.
@B2288 Not all devices have the drawer fill all the horizontal space like desktops. In fact in landscape mode, the drawer usually only take up around 3/4 of the screen.
For me, it's not a big deal because it works and serves its purpose. Perhaps a better design in the future.
@nightshift Can you share a screenshot of your OSK? I don't think there's a change in OTA-10 that could affect the keyboard's height. Perhaps specific to a layout?
@B2288 It was actually added from the initial implementation by Canonical to fix gesture issues when closing the drawer. So now only a righ edge swipe would close the drawer instead of anywhere in the drawer. And this bar with dots is the indicator of this gesture which is the same as the one in the indicators. Design-wise and usability-wise I think it's good but honestly, I agree that it doesn't look good especially in desktop mode.
@halucigenia are you using MultiROM as well or just a regular UT install? If it's the latter, I think there's a command you can use to change the server and channel not sure the exact command though.
@Giiba I honestly can't remember anymore how I did it before and I can't find the APK I used 
@gaspe I think MultiROM's development has stopped as well but I believe it's still working n supported devices. It's quite easy to install. Root, TWRP, install app and you're good to go. If you really can't give up android and want to try UT then try your luck with it 
@domubpkm I recently installed SFOS 3 but I think it's not the latest version available. It's easier to install because it's done via TWRP.
Possible - yes, officially supported - no
I think OPO has MultiROM support, if you know how to modify an APK, you can change the server to UBports instead of the old Canonical server.
It's been working good on my Nexus 5. I currently have Android, SailfishOS and 3 UTs 
But of course, do it at your own risk!
The home button also works on MX4 although I honestly would like to disable it if I can because it can be a conflict with bottom gestures.
In general though, I think home buttons are fine to be enabled but back buttons and recent/menu are kinda doesn't make sense since we don't really have direct equivalent for those and it they will definitely be a distraction in the UT experience
I'm a bit lazy to really read everything in this thread but in my experience, it's always better to install stock android first (I used Nexus Root Toolkit on mine) and then running the UBports installer.
And if you don't mind losing your data, then selecting Wipe might also help