Pros
The most important things I looked for in my job search were engineering challenges; team passion, collaboration, and expertise; a solid product future; and quality of life. Simon nails every single one of those. Since my first day, I haven't looked back. The team here and the product we're building are exactly what I was looking for. Working remotely was a big risk for me since this is my first time doing it (50% of the eng team at Simon is remote). So far it's been a pleasant experience. Some times I miss being in the office (birthdays, etc.), but the benefits otherwise have been great. The leadership team feels very committed to making the remotes feel no different than engineers in HQ.
Cons
Working at a startup has its share of drawbacks, but on the whole I don't really have any non-minor cons. For example, having lots of perks and free snacks would be great, but I'm happy trading those for a passionate, smart group of coworkers. =)