Overall I really like this beta. I am using OS / 2 host and xp as guest.
Important problem: During the optimization tests, I had to kill the virtualbox, and the memory I had in use at the time in the Vbox, it has been locked in OS2, preventing me from restarting xp, until restarting OS / 2 .
Other small problems:
The mouse notepad.exe gets almost transparent and in other similar windows, and changing the icon does not solve the problem.
During the installation of Java 8 ..., the printer, and some other program I have seen small graphical errors, that have not affected for its operation.
If I access a JFS drive it works fine. But if I access a FAT32 drive, the performance is very very slow, but it works !!!
In my case the best balance of memory and screen, have been 768mb of 4gb and 74mb of 128mb screen.
Saludos