Any startup should try to get 15 minutes with Jeff. No matter if he invests or not, he will have amazing feedback and even intro you to other investors. He has a clearly defined focus area (outlined on his site) and he is selective, however, he will also tell you if it it is for him in the meeting.
For us, Jeff was empathetic, resourceful, generous with his time, and always had our best interest at heart. Truly one of the best investor experiences I've had. Will go back to him for future ventures.