My experience here was terrible. At first I thought it was just my department, but issues spanned the whole company.
The HR strategy was laughable, for a company that I'm pretty sure is literally an HR consulting firm themselves. One year, I got a 5 on my performance review (highest score, given to small number of people) and a 1% raise, and a negligible bonus. I left later for a 50% raise, so the low raise certainly wasn't because I was already paid competitively. Lots of HR functions (among other things) were staffed overseas, and it was sometimes hard to get answers to basic questions on things like payroll or benefits.
Senior management seemed particularly incompetent. Maybe it has improved now that John Haley is gone. There was never a clear message from the top about our goals and strategy, and the goals and strategy of different departments often conflicted significantly. There were times where different departments of the company were competing against each other for the same clients.
There was barely any communication from senior management ever, especially not about strategy, but not even about results. That translated to everything seeming like a black box - I'd only know our results if I listened to our earnings calls. Senior management didn't like to share details, and that trickled down to the culture of lower level managers. I never knew how we were doing - they seemed to want to pretend we were doing okay, then surprise us with paltry raises or layoffs.
The only corporate communication we ever got was about D&I and things like Pride Month, Black History Month, Asian and Pacific Islander Month, etc. Which is admirable, I guess, but it seemed very surface-level. Lots of talk and "saying the right things" which is different than actually running a good place to work. I'd rather be receiving corporate communication clearly outlining our results, our goals, our strategy.
Six million directors and senior directors and managing directors and whatever job titles they are using now. Over-inflated egos based on job title, and very bureaucratic. Definitely not a flat organization. Also, the job titles could be pretty inconsistent department to department, depending on how good the team manager was at fighting to make the roles on their team a "good level." For example, you'd have someone with 2 years of experience on one team who was an "Analyst" and someone with identical experience, in a very similar job function, but under a different department/manager, who would be an "Lead Associate." The goal of the job leveling was supposed to keep things fair, but it really just increased the transparency of how unfair things were, and who was likely under or overpaid.
The culture was also generally terrible, with an expectation to work tons of hours (for no pay!). Which I'd have felt better about if it was for a cause or company I cared about, but given that we had no direction or strategy, I felt absolutely no desire to go above and beyond. Also there was a big culture of overselling our capabilities, and lying, instead of actually improving our underlying products and services so that we could sell them in a more honest way.
For what it's worth, Willis Re seemed like it was better-run. Unfortunately for WTW, that's the part they sold off to Gallagher.