After waiting a few weeks I received my new OPI in the mail. By this time I also got a different keyboard that I ordered and what do you know it worked :). But still the whole experience was just slow and not very usable.
I had been googling a bit and found out about a Facebook group that apparently had the GPU drivers for the board. I downloaded the package which came with a long list of instructions. Started to follow them only to get disappointed again about half way through. Turns out the image I'm running on my SD is not quite the right one for that driver...
I turned to the OPI forum again to a thread where one user is gathering a collection of OPI images. I tried a few of them which led to more disappointment. It was a mix and match of keyboard, mouse, ethernet and wifi issues. But before just settling with that slow but workable Lubuntu image I found a thread by a user who had prepared a Debian Jessie image with the GPU driver and some more goodies. I added the link to this project.
Gave the Jessie image a try and surprise, surprise, it works great! It supports my hardware, speed is good and it's able to play audio and video as well. It was even kind enough to remind me to extend my SD partition when I first ran a terminal and it provided a script to do so. None of that manual fdisk rubbish! With the kernel update found on page 2 of the thread I was also able to run in 1080p :). Finally some good news.