Ambrose has a little Roddy Piper and Brian Pillman traits in him or so it seems to me. His FCW/NXT bout a few months ago with @RealKingRegal was stellar. I called it with Dusty Rhodes and we had a blast. Ambrose is a blue chip stock and is arguably the most 'unpredictable' of the three. Perhaps 'complex' is an adequate word to describe Ambrose at this point in time.
Rollins reminds me of @CMPunk in some areas of Rollins' game or at least the formative CM Punk of a few years ago. I perceive that as a good thing. Rollins is an Iowa kid who has a sound, skill set, confidence, toughness and is the current NXT Champion. He has a natural swagger and wrestles with a chip on his shoulder which I embrace.
Reigns is a former Georgia Tech nose tackle and has reshaped his body from 300+ to 260ish and is of Samoan decent, father is WWE HOFer Sika, and at times has reminded me of @TheRock when I first inked 'The Great One' to his WWE contract. In that I mean the obvious heritage matter but also the physical frame, intellect, and overall, natural athleticism. We can only hope that Roman Reigns can approach The Rock's accomplishments inside the squared circle some day. Only time will tell if that lofty goal can be reached but Reigns can be special. Watch someone interpret what I just said as being that JR is predicting Roman to be the next Rock. Hey, I wish.