Not so much a con as it is something for people to know—this company is an amazing opportunity for someone who is very self-driven, up for a challenge, not satisfied with the status quo, and has an insatiable quest for knowledge and self-improvement. If that doesn't sound like you, this isn't the right place for you, and that's OK. The hiring bar is exceptionally high and it's not in vain—I've honestly never worked with such intelligent people in my life, and these people get more done in a day than I ever thought possible. You'll feel like you're never doing enough and that you're not performing as well as you can. But they wouldn't have hired you if they thought you couldn't take it, so enjoy the ride and remember that this is seriously the best career opportunity out there.