Its pretty good, if I do say so myself. It is built out of abs plastic, the rods are industry standard 15mm, spaced at 60mm centre to centre. There is lateral movement but no vertical. But I can still line up my cam with my mattebox. I'll try and get some pics up.
Well, that is the standard. Although, I think there are smaller rods for specific matteboxes, like Cavision, and the Century Optics, but predominately the rods are 15mm. Now as for the 60mm centre to centre, there is also 100mm centre to centre for larger cinema cams and their associated baseplates, like for an ARRISR16, or 435 or 535. These bigger bases are usually for tripod work or studio work. But those are 15mm rods. Now that I think about it there are bigger rods, 19mm as well but I could be wrong.
The baseplate is made from ABS plastic. The support at the front is a Cavision support that I got with my 4x4 MB. You can buy them seperate or you can buy the Cavision rails system and it comes with one.