The BBC version seems a lot less "Hollywood", and admittedly a lot fewer deals are made. However the interaction tends to be a little more business orientated and the conclusions more valuable.
Later seasons dropped this, they go into the business side in less depth, and even the editing became lazy (you can predict who's going to get a deal when they walk in by just looking at your watch.)
They pick the contestants in terms whos the most loopy /and or will make the best TV.
And watching the live versions of Dragons Den they also did at some of these shows its brutally obvious that the Dragons are all property developers plus an accountant who got lucky and when they get a real high tech biotechstart-up pitching them the blank looks on their faces was priceless.