Pros
Having worked at other startups in the same and other industries before, I can confidently say that these guys know what they're doing. The camaraderie and comfortable feel of the culture lead to great teamwork. They are fairly flexible with hours, expecting you to only work 9-5 on a regular basis (plus an hour lunch, which comes out to 7hrs per day - unheard of in *any* company), with the understanding that when deadlines are crunching, you'll be able to ramp up and occasionally stay late when needed. If you do have to stay late to get something done, the management is good about staying right there with you so that you're all working together (and they usually buy pizza too!). This is not the life you normally find in a young company/startup. In my experience, a typical week is closer to 50+ hours per for a startup (especially in engineering) and you are silently judged if you go home before 6pm.
Benefits are great and pay is good across the board - they believe in fair wages and taking care of their people, and our monthly Altavalunches are a wonderful extra perk.
Also - best holiday party on the planet. Hands down.
Cons
While you are at work, you are expected to be working; spending all day on Facebook or Reddit is not tolerated well.
When those project deadlines come - like they do for all small companies and startups - be prepared to work hard and put in the time, but again, they work side-by-side with you and don't expect you to just handle it while they go home and relax.