Pros
Zillow is a great company to work for. Salaries are competitive and they make a strong effort to keep them fair as well as even with the market. Zillow is also very fair with raises and stock equity grants. As far as personal growth, Zillow encourages you in its core values to Own It. You get ahead at Zillow by owning big projects, taking big swings, and succeeding at them. Zillow as a large company is also very generous. Every year employees get a very cool gift that has a purpose, to make us better at our jobs. Last year was FitBits (good health means good work), this year it was Kindle Fires (smarter employees are better employees).
Cons
Zillow has historically been weak on training, but that is changing quickly. I think the biggest con is that it can be difficult to be in an office other than main headquarters, and can also be difficult to work on a business that is not the core real estate/for sale business.