I was never one to bother with Little Britain, but downloaded LB Abroad, and 'Come Fly With Me'
Well, they were interviewed the other day and said they were given quite a lot of freedom, which is how they were allowed to do 'Precious' (coloured lady running coffee and tea kiosk) and so on.
I just found the portrayals particularly weak, but perhaps some of the props were deliberately shoddy to remind people these were not real people, just a couple of actors/comics playing stereotypes.
I did not find it offensive, and had a giggle here and there (rather like scoobytoo, because some of the individuals on Airport/Airline etc had some parallels in this show), but it was nothing to compare with comedy of old, in my opinion.
It may also have been a touch funnier for me because I missed out on a few years of Airport/Airline shows and they are being re-run on Sky etc so I have seen some recent reminders.
Lucas and Walliams as the airport photographers missing the 'star' was funny in that they were doing a silly sing-song as she walked past, but the two in the original TV show were a bit daft as well, trying to get a special photo and sometimes messing up...