I worked at Key Events for many years and saw it evolve from 3 people to 20+ and beyond. They've grown even more in the past couple of years. The one constant was the opportunity to work on incredible client programs and learn all aspects of event management from CEO Heather Keenan. You definitely get a chance to roll up your sleeves and become well-versed in the intricacies of the industry.
Cons
This career path has waves of long hours - but that is the norm.