Pros
There are certainly some pros for working at the big G, mostly being that one will generally get to work on some extremely exciting and unique projects. It is a great resume builder, and overall (not always) my work-life balance was pretty good, but that was also because I approach it that way. Despite taking a pay cut when joining, I wouldn't trade the experience I gained while there for anything. Like most places, people were generally nice. Benefits are pretty average in my experience, but the number of PTO days is nice compared to their peers.
Cons
While people were generally nice, the politics and favoritism of Gensler is painfully obvious, and being knowledgeable or experienced isn't necessarily beneficial to an employee. The design director, at least while there, wasn't even licensed in her field, and the managing director is absolutely horrid - terrible people skills, not particularly strong at conceptual or technical design. Know that at a firm like Gensler, anyone can be on the chopping block at any moment (such as, during Covid but your projects never stopped but there was a firing quota to meet anyway). These people do not know how to use Revit properly, and don't even have real standards. Efficiency is not rewarded at all, and employees willing to work extra hours, despite being inefficient and capably of getting their work done within a 40-hour week, will be praised for 'going above and beyond.' Gensler if definitely just another large company that says one thing is their value, but the day to day that goes completely unseen. I feel being at one of the bigger offices would have been an overall better experience, but the Philly office basically just shouldn't exist, honestly.