Pros
Company is committed to helping people and making genetic tests widespread.
Mendelics is doing real science (genomics, bioinformatics) and gives employees a lot of room to try new things. There is a lot of incentive to explore new methods, tools, etc.
Most employees are extremely bright and work environment very good.
Pay is above average for most positions, benefits as well, but no fluff.
Cons
Company is growing fast and there is always more work than people can handle. Processes are constantly changing due to changes in scale/demand. Never a dull moment. (a little too much of that)
Management has been sometimes taken too long to fire bad employees.