Pros
It's a lovely physical working environment, beautiful surroundings and nice offices. There's a pub onsite, a shop and lovely walks in the summer. There is always plenty of legal work so you'll never get bored and people are generally nice, educated and polite.
Cons
You need to be aggressive, focused and ambitious to get ahead at AZ. It's very much who you know, not how well you do. Managers have been there for years and don't want to go anywhere else, so they are not particularly progressive (eg flexible working as an alien concept when I was there). Salaries are not the highest and bonuses tend to be on the low side, but that depends on where you are in the organisation. I worked like a dog on a long term project and was given a bonus of £2k whereas the project manager's bonus enabled him to buy a house in Italy! Hmmm, bit of a mismatch there since I probably spent longer on the project than he did.