Consulting in general is an incredible start to a career as you develop the full gambit of business skills/experience. Venture is an even better opportunity as the small size means you're learning directly from the CEO - who is an incredible thinker- and exposed to a wide variety of clients and cases. i.e. no getting stuck on one client/case or doing one type of analysis for months and months on end. Furthermore, in a small team high performers shine- meaning responsibility and promotion follow.
Cons
Like all professional services, the hours can be long when you start. There's also less structure/ organizational overhead than more established firms so you have to be willing to upwardly manage / fearlessly communicate with management.