Pros
Leadership, training, culture, compensation, growth opportunity, product, client satisfaction, hires elite talent so you know you're in great company, strategic, surrounded by hard working individuals that put a lot of passion into their work from upper management to entry level employees, dedicated to innovation, sales has huge support from marketing, management actually cares about their employees, competitive spirit, exciting time to be a part of a growing and successful company.
Cons
Product is always evolving but sometimes the processes to support those changes are slower to catch up, typical growth pains, not easy, not a fit for everyone but that's why those who succeed stay long, work hard and appreciate the opportunity.