Ph.D flopper may not explode if the player is standing up or crouched when landing from a high fall. The most assured way to use Ph.D flopper is to use it when diving.
Ph.D flopper eliminates the occasional Infinite blast radius on grenades and betties.
The strength of the explosion caused by Ph.D flopper depends on how long the player fell before hitting the ground. It can also do extra damage with high gravity situations.
Pro's- Nice price, eliminates fall damage, turns the player into a weapon.
cons- Doesn't always do it's job. (glitch or coding error.)