Pros
The people are great. Everyone is really smart, nice to work with, and they care about the customer and the product. People don't lose their temper and they all handle stress well. The pay and perks are good. For a while they were pushing pretty long work hours, but it seems to have mellowed out some. The product is great and the customers love it. I think the company is going to be a huge success.
Cons
I've worked at big companies and small companies, and I've never experienced such a top down management style. People are constantly waiting for orders, permission, or approval from higher up. Managers and even execs don't have the authority to approve most things, so it often has to go to the CEO. It feels slow and feels like the people making the decisions don't take time to make them well. Some people try to sneak work through without permission (do first, ask forgiveness later), but usually they get caught. Some people just check out. A couple of engineers who used to work really hard are 9 to 5ing it now. It's hard to quit because the people and product are so great and I think the stock options are going to be worth something someday. A lot of other software people are job hunting.