Pros
I will be speaking from an engineering perspective, don't have much exposure to sales. Probably the best thing about Keeper is that it is a huge learning opportunity. By the nature of the business, the domain knowledge is not that deep (secure record keeping, you cannot compare it with LOB systems) but the company tries to cover all platforms and many technologies that are out there. So at Keeper, you can either stick to the technology you love or try something new in one of the multiple teams centered around products or services. In addition, learning crypto makes you a better engineer and raises your value on the market. The management style is startup-like (which is good for people who can appreciate it ;), but schedule is normal, pushes to complete a project on time happen, but relatively rare. Location is greatest in Sacramento area, easy to reach, easy to park, nice restaurants, etc. Team is great, a lot of highly skilled, experienced and energetic people.
Cons
One man's Pros are another man Cons'es ;) If you don't like to learn and to solve hard problems, you might not fit in.