Thanks to Netflix I have now watched both seasons of the original "The Office" which aired on the BBC. I think the old adage that the Americans and the British are a peoples separated by a common language. Some of the jokes just didn't translate very well and a lot of the dialog seemed to be mumbled at a fast rate. I also think that the overall flow of culture seems to be more towards England as opposed to the opposite direction, so that perhaps our cultural references would understood there, but their cultural references would be lost to American audiences. Overall it was a funny series that I enjoyed, however I much prefer the American version. The US cast may be a little more over-the-top, but that just adds to the humor. Many of the secondary characters also get developed much better in the US version, so there's a little more depth.
The one thing the British version had going for it was that it was essentially R-rated while the US version is pretty much restricted to the PG-13 limit. There were many funny jokes related to dildos and giant inflatable cocks that will never translate to American television (stupid censors!). Language was also kicked up a notch.
So I still have to catch up with season 4 of the American version before season 5 soon starts on NBC. The British version only lasted 2 years sadly (with a special episode as a 3rd season). It seemed that they were just hitting their stride when the show was canceled. All I know is that as bad as my boss is, I'm very glad that I don't have a Michael Scott or a David Brent supervising me.