Pros
I worked with people who I got on with well. We were almost like a family, which made the cons (below) far more bearable. This was in part due to the employee referral scheme being used for the majority of new positions that opened up. It's fair to say that the majority of the pros during my time with ALcontrol were a result of a workforce that felt as much like a family as a random group of people being paid by the same company.
Cons
Labs frequently accept work above their capacity. This means that staff are not *technically* obliged to do overtime, but will frequently be dragged into it or treated as though they're "not a team player". The accepting work above capacity also leads to poor house-keeping purely due to the amount of space available, and causes great frustration when all you want is the space to do your job properly. Also of great frustration is that investment in infrastructure to cope with additional work is very uneven, the flagship lab gets a lot of money spent on it, where as the lab I worked in even three years after I left looked much as I joined it (three years prior to me leaving!). This makes employees feel under-valued and creates an atmosphere of "they don't care, why should we?" among less conscientious employees, which when you look at ALcontrols pay scale, will be a lot of them.