I saw it last night at an advance preview. Thought it was largely very good.
The first half is far funnier than the second, as you start to realise that these guys might actually end up dead. Some great lines of dialogue (it's co-written by Armstrong and Bains from Peep Show / Thick of it) and cameos (Julia Davis as a homophobic skaghead neighbour and Kevin Eldon as an indescriminate sniper).
Some scenes are a bit uncomfortable, like the family dynamic and it will be controversial purely because of it's subject matter. But largely it's an old school slapstick 'idiots' film where 2 or 3 easily led morons are reliant on their slightly less stupid friend to lead them through life, resulting in some great physical comedy, clever wordplay and plain idiocy.
It asks a few interesting questions too and makes a few snide remarks about the country's attitude towards terrorism.
Well worth a watch. And watch out for the 'mini babybell' line...