Hydrashok's are "competive" bullets, but there are better choices out there, including the HST.
Testing had been conducted to determine the effective of the post on expansion and testing was done with the post intact, and with the post removed. The results can be reviewed at the firearms tactical institue web site. When the hydrashok expands, its a very potent bullet designt and its very effective. However, the design of the bullet can make for less reliable expansion. Hydrshoks have a tendency to collect denim, wood or other debris in the cavity of the bullet, clogging it and preventing it from expanding. When this happens, it penetrates similarly to a 9mm FMJ and wounds about the same. This could make for a very "dangerous" round to use in a HD weapon there is a greater risk of overpentration with this round, as opposed to other bullets. In a real world shooting, against somone wearing light clothing you could probably expect 1 out of 2 rounds to expand properly....which isn't horrible, but its not great. Hydrshoks are a tried and true bullet design that has been used by many LE agencies, and continues to see service to this day. That being said, its an older bullet design with some limitations and there are newer/better bullet designs that offer better and more reliable performance.