Pros
Improving is hands-down the best place I've ever worked. They've invested in countless ways in my growth and in the culture we all enjoy. That does not mean it is 'free'. You opt in to that growth and a lot of the benefits by your choices. It's in what you give beyond the 40. That can feel daunting, but if you are diligent and pick your contributions well, it is very rewarding and gives you much more direct control of what you earn and where you grow!
Cons
Improving is very intentional about our culture, and it is not a good fit for everyone. That can be perceived as imposing, or other negative sentiments. The truth is that the patterns of behavior that culture creates are what make Improving who we are, and give like to the quality of work we deliver. Since this is opt-in as well, it can feel like a choice to 'drink the koolaid' or get kicked off the island. The right way instead to approach it is to find your 'flavor' or 'version' of implmenting the existing cultural values. Improving wants for you to own your delivery, but is very clear about what the hallmarks of that delivery must be. The best Improvers make it their own, but there is little guidance on doing this successfully.