Some parts are different. One thing that put me off was that the boss wasn't an insane lunatic that did random things. The boss is the US version was a more collected, planning and evil character.

Like the scene where he called back after firing an entire department to say "I was just keeping the IT-department in line", suggesting that he knew what they where up to all along.

The UK boss wouldn't do that. He would keep doing things that only made sense to his insane brain, until something went down hill enough that he just jumped out of a window in the middle of a meeting.