Dropping weights is something that, in an emergency, you should consider doing ONCE YOU'VE REACHED THE SURFACE ... in order to prevent you from sinking again. It's not something that you should consider doing while submerged except in the most dire of circumstances.
Dropping weights results in an uncontrolled buoyant ascent ... in other words, you're going to the surface at a rate that you cannot control ... and if you are wearing a wetsuit, a rate that will increase as you get closer to the surface. This can be very hazardous.
For that reason, no ... I've never done it ... the only reason I would ever consider it is if I were faced with a choice of dropping weights and potentially injuring/killing myself or not dropping them and facing a certain death. Otherwise, I'm going to make a more controlled ascent by swimming myself up while wearing my weights.
... Bob (Grateful Diver)