I just bought the Mark V pro. I haven't riden it yet, It is at the powder coaters, but I will give you my opinion on what I have experienced so far.

All the frames have the same geometry, except the Angus has a threaded 1" head tube. The fork is EXTREMELY heavy. Almost weighs as much as the frame. The difference between the Mark V and the Pro, is the brake guides and the rear brake drilling. The rear track ends are kind of funky. They sort of go on the inside of the tubing, and it is a turn off. You can bar spin! Now I have to learn to bar spin! But overall, it feels like a good solid bike, and they are cheap enough to buy and powder coat (at least that was my draw)