Pros
The physical environment is pleasant. The building is modern and impressive and, as another reviewer noted the restaurant is excellent. Every day fruit and pastries are delivered mid-morning and decent coffee, tea and chocolate biscuits are free and plentiful. The standard of engineering can be high and the people are pretty sharp.
Cons
The longer you stay at Sophos the poorer you become. Pay rises are always a disappointment. I don't think I've ever been quite so micromanaged either. But not to good effect. Months of idleness while people chat ( they love a good meeting at Sophos ) followed by disorganised panic. The build system is pretty complicated too. Humourously so on occasion. Best of all, no decision is too trivial to be taken over and over again by people more important than you.