Pros
Well-funded (aka promising) startup working on a cool tech product, which makes for a team of passionate and excited people. Founders are also the main investors so they are very involved with the company and really seem to have the best interest of their employees in mind. Very flexible work environment (at least on the marketing team); friendly, down-to-earth and driven team members. Management is open-minded to moving team members around to positions that best suit their individual skill set, so lots of opportunity to shine.
Cons
An environment that's not for everyone. People who are not very self-motivated or need a lot of predetermined structure/aren't able to independently structure their time outside of a traditional office don't seem to mesh well. This is especially true for independent contractors who need to show that they are producing work that matches with the hours they report.