So I got my MiBox 4K. Set up and installed with no problems. Netflix and TED working like they should.
There was no browser pre-installed and I was surprised to find that Chrome isn't available for Android TV.
I side-loaded it but there was no mouse pointer. Side loaded a couple of other browsers that I have on my phone but they were displayed sideways and no pointer.
I did find a purpose built browser and downloaded a remote app for the phone which functions as a d-pad and keyboard. I don't see myself doing a lot of browsing, but if I do I will look at bluetooth keyboard and trackpad.