Installed the released amd64 version of Kubuntu in a VirtualBox virtual machine - single CPU, 4096 Gb memory, 128 Mb video memory, single monitor. After install, following instructions from several blogs/websites, did :-
sudo apt-get update
sudo apt-get install linux-headers-generic-$(uname -r) dkms virtualbox- guest-dkms build-essential module-assistant
(linux-headers-generic-whatever already latest here)
sudo m-a prepare insert guest-additions iso
install GA then reboot VM starts OK, logged in normally and the desktop/panel looks fine, window full screen. However, move the mouse pointer anywhere near the panel and it disappears. The desktop is not responsive and no right-click menu. Any program started via alt+ f2 also disappears on to the vanished panel. Moving the mouse pointer down shows the program pre-view but it is not responsive. I don't seem to be able to actually do anything so am unable to use this distro.
I have not tried to install to a hard drive yet.
Linuxmint 17.3 behaves perfectly BTW - so does ubuntu 14.04. I will try the ubuntu 16.04 release some time in Vbox and kubuntu 16.04 to HD later.