There are many reviews up here, on Amazon, from rubbish to brilliant.
Sean Bean IS Bean (Sean, not the Mr Bean, that's briefly seen on TV) and that's not a bad thing - you know what you are getting with him and here he delivers. Charlotte Rampling adds gravitas and class as a top MI6 boss, though she doesn't have much screen time.
The violence is where it needs to be, story-wise and very well done. Strong, to the point, it pulls no punches but is fairly restrained in its quantity. The London locations make it very real to us Brits and whilst a little 'TV Episode-ish' at times (Spooks has been uttered, more than once) this is a quality, extra-length feature episode.
The story, about Muslims living in London and terrorist cells is both relevant and of course, controversial and everyone will have their own opinion and stance on this and so I'm not 'going there'. However, in comparison to those TV dramas mentioned before, this one seems a lot more complete and sensical and thus, more satisfying, overall.
However, the star has to be almost unknown writer/director Hadi Hajaig. I could find almost nothing about him on IMDb, but that source estimated the film's budget as a mere £2 million. That might sound a lot to you and me, but it really is peanuts, especially when filming in - and over - one of the most expensive cities in the world - and for a 105 min feature film and decent cast, with a couple of real stars, too. At no time did I feel the direction lacking, a bit unexceptional and ordinary, maybe but it always did what it had to. I also found the music suitably rousing/poignant, too.
I saw this on Sky Movies and whilst it was good overall, both the subject matter (a bit grizzly, to be honest) and that it didn't scream 'watch me again' suggests that this is a good rental or TV watch - and thus 3.5 stars.