-General lack of startup experience at every level in the company means a lot of first-timer mistakes as the company scales. This is a little risky for big strategy decisions about the direction of the company. Can be a pro since everyone grows together and is excited about their work.
-Not the most professional work environment. Could also be a pro, depends on what you're looking for.
-Employees have very strong personalities, so it's pretty hit or miss as to whether or not you'll fit in to the office vibe and which people you'll get along with.
-The compensation culture at Magoosh may turn off people who are aggressive about moving up the corporate ladder and focusing on maximizing personal financial growth. You'll get a lot of fuzzy good feelings and enjoy your daily work, but if you're looking for the competitive, financially incentivized environment that a lot of growing tech startups offer, this is not the place.