Pros
The founders are always trying to do what's right by their customers and employees. Leadership team consist of highly capable and intelligent people (but character and values are not necessarily always the same as the founders'). Fast-growth company means you have to constantly develop yourself or you will not be able to keep up with increasing business needs. Not quite as draconian as an up-or-out model; but definitely not the place for you to work at a casual pace. I personally love this; but I'm well aware that not everyone feel the same way.
Cons
Depending on the team and manager, some have absolutely top-notch A-players; others not so much. So the performance expectations and employee experience are not consistent between different groups.
