The trailer for this movie actually represents what you get very, very well. Quite a bit of gore and funny moments. In fact, I thought that I would find it less funny than I did. There is some really witty writing here.
However, what already bothered me in the trailer really did not sit well with me in the movie too. Namely when the writing goes from witty to dim-witted. Mostly because of those one-liners. Although even some of the serious dialog seems just too unnatural and clichéd.
Also, for my taste, there is a little bit too much cutting to a certain location where people are stuck. There is nothing going on aside from some of the pretty awful dialog I just referred to.
A minor complaint, since there is still plenty of gory action going on, would be that there are some scenes in which gore spatters from off-screen where I would have preferred to see the action on-screen.
In the end, it is about a fun, gory ride and "Cockneys vs Zombies" sure delivers when it comes to that. However, productions such as "Tucker and Dale vs Evil" or "Shaun of the Dead" have demonstrated that one doesn't have to rely on formulaic dialog and one-liners so heavily in order to create a fun splatter film that is actually fun.