You can apply to become a member to get dedicated seating or even a glass cubicle office, but basically, a order of a drinks would allow you to stay for as long as you wish. Most packed on weekend afternoons, but could usually squeeze. You'd be very safe to go on weekdays (both daytime or evening). They also served some light food, "Ramen in a Blue Bowl" (ramen with a few slices of tomatoes and some veggies) is a life saver when you'r striving hard to work. Coffee, like any cafes in Taipei, is pretty great to me. Super helpful staff, inspiring crowd and tasteful music.