I took a while to get on with it at first, it's far from perfect and the character switching thing doesn't quite fulfill the promise but embrace the flaws and play in relatively short bursts to avoid repetition and it's great fun. I'd advise turning the permadeath thing on so if one of your guys is done they're gone for good, and just use the tube or drone to get around as driving is one of the main reasons I didn't enjoy it originally
Pretty much echo what ajsccfc says. If you've played a watchdogs game before it'll all be pretty similar. It was the London setting that sold it for me. Cool to drive around and recognise places you've been in real life. I also play with permadeath on which is a bit of a bummer when you lose a character you have a bit of an affinity with. Although, that is the point, raises the stakes a bit. The accents are ridiculous sometimes. I like the overall story threads though, enough there to keep you interested and want to know how it plays out.