Pros
Overall, Imagination has a longstanding reputation of hiring really talented people. That number seems to be decreasing, however, due to salaries under industry standards and insane work flow. There's a lot of effort poured into creating a community culture. And for those who love working on print magazines, it's rewarding work.
Cons
The C-Suite, if you want to call it that, is completely inept. Jim Meyers essentially makes all business decisions based on his ego, routinely ignoring pleas from everyone around him and bullying his staff. Because of that, clients walk all over the company and Imagination is usually pouring its own money and labor well beyond scope. The people who suffer most from this are the people executing the work who are rarely rewarded for their efforts. Jim loves to force staff members into hour long-plus meetings where he can brag about meeting some CEO who impressed him or some book he read on thought leadership and how this epiphany is creating innovation at his company that never comes into play. It usually consists of some self-flattering grand gesture rather than something tangible, you know, like providing actual raises or bonuses. You won't get any of those, by the way, except literally a $100 bill in an envelope at Christmas and a party at the dive bar next door. I have friends who are admins who are treated better than this company treats senior level staff. Upwards mobility is a joke. The company is always "restructuring" and now doing quarterly reviews to create bogus titles as a way of skirting raises. Reviews would be great if they involved any reward but usually just result in more paperwork for already overworked employees. Jim doesn't understand digital, so if you talk great game about digital and use excessive buzzwords, you'll be a company favorite. Nevermind if you work on things that actually make them money or gain recognition. Oh, did I even mention work yet? You'll be expected to answer emails and calls 24/7, and on vacation. This is because they're so understaffed and unwilling to hire replacements that you'll be the only one capable of handling a project. I don't really understand how you can go above and beyond when everyone is already tasked with ridiculous feats every day. Office politics here are painfully toxic. The upside is the turnover is so frequent that the person being a jerk to you today likely won't be there the same time next year.