I got offers from both Brunel and Surrey, but I went for Surrey in the end.
Brunel do not offer many "optional" modules so you have to follow a set course structure and you cannot choose what modules you want to take, as I found out at their open day. Also, Surrey seems to be much higher rated in both the Guardian and Times uni course rankings for Computer Science, and the uni has one of the best graduate employment rates in the country. Both unis have good train links to London so I wouldn't worry about the quality of your work placement.
Surrey requires A-level maths though, so if you haven't got that then there isn't much point in applying but you won't need maths with Brunel.