Testing conducted to enable a user/customer to determine whether to accept a software product. Normally performed to validate the software meets a set of agreed acceptance criteria.
Cons
A testing phase where the tester tries to 'break' the system by randomly trying the system's functionality. Can include negative testing as well. See also Monkey Testing.
They bought you lunch a few times a year. They appeared friendly at least to your face. Climate controlled building.
Cons
Good old boys network. Like maybe 6-8 techs were treated very well and could do no wrong. You'd find out on a Friday that you would be working the entire holiday weekend, plans or not.