The Ubersaw will charge up the medic's ubercharge/kritzkreig meter by 25% on a successful hit of an enemy, but It swings 20% slower than the normal Bonesaw. The current charge level is shown off in the saw's inner syringe. The medic can still use the Ubersaw on Scout s while they are under the effects of Bonk! Atomic Punch. It will cause the Scout zero damage, but it will still fill the saw with Ubercharge just the same.
A taunt kill called Spinal Tap Attack has been added to the Ubersaw on January 13 2010, in which the Medic will thrust the saw into the enemy causing an instant kill.