Angus is made of 631 steel. That's nicer.

Mark V takes a 1 1/8" (modern) headset. (arguably nicer)

Mark V Pro combines both features, but all they have left are 62cm (X large.) It's a limited run.

Personally I like the look of the old style 1" stems so I'd go with an Angus.

For full disclosure, I'm expecting the Pro tomorrow via UPS. So I guess this advice is based on my own pre-purchase research, and not experience with these bikes.