It was fashionable to bash PA on here for a while wasn't it, don't hear as much of it anymore. Much of it based on a data loss from one of their techies. In reality they're a very stable consulting business. Public Sector has been a big source of this but they have a lot more work in non-PS service industries now, manufacturing as well.
Probably not as appealing as a brand for a junior IT bod, but experienced hires I've spoken to in more operations consulting over the last few years have quite a lot of positives to say.
Culture, progression, management style can be dependent on the team / area but that's the same as most organisations. Broadly quite a flat structure though. Talk to them and see what you think.