Pros
Good & friendly work colleagues, based in an excellent London location. Also, a renowned company to be with if you're specifically looking for experience in the publishing sector. Whilst not everyone has heard of Elsevier, they will probably have heard of some of the publications that they produce. Fairly good employee benefits (i.e. pay & pension).
Cons
Like most large companies during times of recession, Elsevier decided to tighten up it's business, taking away responsibility from local offices, and focusing more on a central management approach (largely from the US). From speaking to colleagues who had been there for over 10 years, they had seen how Elsevier had gone from a smaller publishing firm, with good employee relations, a focus on local production and a certain amount of local autonomy, to merging/buying up/bought out with other companies to become a much larger, generic, corporate entity. Even in the relatively short time that I was there, you could see the changes, including the redundancies.