gliding angle and time
I read in all books in my life that the gliding path don't changes with weight, just time rate of descent, the speed and the time.
With increased weight, the speed should be increased to keep the angle of attack at optimum. This would increase the rate of descent, the speed, reduce time and mantain the distance.
The 737-300's manual states that the distance to descent increases with weight, althought the descent speed is the same with all weights. That just don't fit in my head.
If you mantain the same speed and increase weight, the angle of attack will increase, the drag will be higher and the distance should be shorter.
The only explanation I can imagine is that the increased weight increases the distance required to reduce speed at 10,000ft and on approach.