Pros
I can not think of a single pro.
Cons
Employee welfare was never taken into consideration, it was a nightmare to ever get through to HR, expected to work unreasonable hours and treated like a general dogs body. Manager was utterly useless and cared more about impressing the client than the fact you had so much work to do you didn't even have time to go to the loo or get a drink. When I raised my concerns they fell on deaf ears. I would NEVER work for this company or recommend them to anyone. My direct line manager was "fired" whilst on holiday, she came back to a phone call asking her not to return to the client site and they had blocked her pass so she could not get in. She had no idea this was happening, it was very underhanded and shocking.