Only downside (at Iron at least) of being owned by a huge company is the occasional silly training videos. Otherwise they don't bother Iron too much.
Change happens, but some of it happens very slowly. Some technology pretty old (although not all)
If you're in development/QA, you have releases on Saturday nights once per 6 weeks
Work-from-home flexibility is there to a certain extent. But if you're looking for somewhere to work from home all the time to, this isn't it.