Pros
No crunch (although that's really a pro only in game dev). There are some nice benefits like Cycle Scheme, the pension scheme, relocation bonus (if applicable). You can work fully remote from anywhere in the UK.
Cons
Horsham is a boring town. Salary is pretty low. Next issues are project-specific. Code quality is really bad. It's basically cowboy coding all the way. Some examples: Some programmers use camel case, other snake case for the same type of symbols in the same class. C++ access specifiers lose all meaning. C++ core guidelines are a foreign term. Development basically works through bug fixing. Half-finished feature is pushed into production and then patched until no QA notices anything. Barely any inter-team collaboration resulting in stuff needing to be rewritten. Very superficial automated testing. No systems to address tech debt (it's either absolutely burning issue or it can be done later). CA is really reluctant to promote you. 1-to-1s with my lead didn't contain any career path discussion unless I brought it up. Complaints brough up at sparse retrospectives are rarely addressed. I think the root of all these is company culture which can be summarized by the line "well, it sucks but whatcha gonna do?"