The point is, when you fire a couple shots here and there, and you forget how many, and then you see an area with a bunch of guys, so you think, "Hmmmm, how many darts do i have left?" so you take out your clip, see how many darts, and get ambushed. Thats what i think the point is. I think it is really cool.
I can easily see how one may lose count, especially with modified high capacity magazines. I think it would be very "cool" to have one upon your weapon if nothing else. I hope the poster is continues with the idea and is successful in his endeavor despite the negative posts here dissuading him from pursuing this. (Though being a fan of steampunk, I woudl probably use some sort of gauge or clock face to display the rounds )