As a Yank, it's quite hard to see "Mock the Week" with any regularity (Thanks, YouTube!). While it IS true that there is material in this show that HAS been on "Mock the Week", there is material that hasn't been on the show, and also, as a live show, there are responses to heckles and audience participation (there's one such response to an oil rig worker in his extra "F-ck You Scotland" that made the extra worth watching), some of which are singularly guffaw-worthy.
I did take issue, as another reviewer did, the fact that one line seemed a bit disingenuous as to its origin, but overall, I find this DVD a worthy buy, especially as a Frankie Boyle fan, and doubly especially as someone who lives in the U.S.
The show is basically a series of offensive one-liners, as opposed to a series of narratives (like Dara Ó Briain), so anyone who doesn't take to that kind of humor might not be happy with the experience. I, however, can't get enough of it!