Pros
The founders have done a great job finding the right investors to support the mission and hiring a strong initial team to build out the capabilities. This company is playing to win, and taking care of its people in the process. There is a lot to do, so work can be intense, but with ample room to rest and avoid burnout. The intensity also means significance in that every person on the team matters, and their execution every day matters.
Cons
The intensity and risk of a young startup solving hard problems might be considered a con by some. Change is rapid, which can feel somewhat chaotic.