The British version is clinical with cold and cutting critiques and bastard judges who only crack smiles at the expense of the contestants... and you love them for it. The contestants are all business, coming in only for the challenges and returning to their ordinary lives otherwise... the show is just test after test with the growth of the challengers occurring off screen, on their own time, if any at all.
The AU version is exceedingly warm, fuzzy, and full of heart where the judges are mentors and cheerleaders for the contestants who all come to comrades and friends through the intense culinary boot camp. The contestants seem like normal humble people who come out of their shells and into their skills through the course of the competition. It's heart-warming, tear jerking, and awe-inspiring but takes nearly 80 episodes to get its point across.
The US version seems like a terrible combination of the worst of both. Any semblance of professionalism from the British version is destroyed by Ramsey's artificial attempts to inject heart or drama and bullying the other judges into having his way. On the other hand, the heart is slain by having cruel judges and- again- batsh*t insane Ramsey who can go off at any minute in a rage- plus the genuine nature is tempered by the shorter format and forced drama.
That said... it looks miles better than "Jerry Springer with cooks" Hell's Kitchen. The format seems closer to the AU version (which seems closer to American tastes) and if they can avoid some of the shenanigans of the AU version it could at least be a contender amongst serial competition food TV.