It's a really interesting series IMO, especially since I've followed BBFC censorship pretty closely over the years (at the start of the DVD era I imported shitloads of DVDs from the USA because so many were cut in the UK, even getting myself a region-free DVD player when it was quite an expensive endeavour to do so!).
The current situation is films getting cut to 'fit' a certificate, rather than the MPAA (USA) or the BBFC (UK) demanding the cuts be made. (The BBFC have had a policy for a decade or more now where they only cut at 18 if the content would breach the law, but in the 90s in the Ferman era they were very censorial and all sorts of routine action/thriller films got cut for violence. These days the MPAA are probably the prissier of the two bodies, especially when it comes to sexual content.)
For example World War Z (the recent Brad Pitt zombie film) was absolutely hacked to shreds to get its PG-13 rating in the States (an uncut 'R' was available) just to increase its commercial appeal. The Unrated cut is like a completely different film.
I really hate watching cut films so always track down the uncut/Unrated/uprated version where possible when watching a film.