Pros
I say it's the best "first" job because by being expected to work on the full stack, and being surrounded by the most intelligent and helpful people you will ever meet, you learn a ton of software engineering skills very quickly. Also I want to note that in the time I've been here, the company has been growing quite a bit, and some of us had started getting concerned about losing some important parts of our culture, but upper management took this issue very seriously. The CEO himself set aside a lot of time to chat with us in a small group setting about specific aspects of the culture that we felt were important to maintain. I'm not sure exactly how much an hour of his time is worth in company dollars, but it absolutely solidified my company spirit. We're getting bigger, but not too big to care about the little things.
Cons
There was a time earlier this year when things got hectic. It was not a good time. I think that has passed. Let's hope it doesn't happen again. (Then again, I suppose there are a lot of companies out there which constantly have that level of stress.)