they are very flat. I have a 158.5 g r-pro boss and it was much much more understable than any star or champion boss I have. I have bought 8-9 seperate boss discs to try to hit the 400 ft mark with consistency. I always order the lightest but once I weigh them they are heavy, at least 173 g. These Boss discs feel too big for my hand or something and I'm not a small guy... However the Pro Boss feels like it is smaller and I can put a tremendous amount of snap on the disc rather easily. It flies low and slightly to the right. Usually I can throw it between 350-400 and it is my second farthest disc behind my 170g star destroyer which i can crush. I would definately get a couple of them, one about 160g to throw backhand. I personally love my 167g star boss for a mid to long range flick disc as well, and have found it is very easy to control distance with a slight hyzer.
Overall I love the pro boss for open range or low ceiling long straight drives