The performance of the Hydra Shok Deep in this test wasn't particularly impressive IMO...not bad but it seems to be inferior to HST. The 9mm version does seem to perform pretty well in short barrels.
The author of the article is mistaken about the damage tracts; handgun hollowpoints expand more or less completely after the first 1-3 inches of penetration. The increased disturbance seen earlier on in the track is simply an effect of the temporary cavity and doesn't actually remain in flesh. It's an understandable misconception, I used to think the same until I learned that the permanent cavity seen in ballistic gel is not reflective of actual tissue. For practical intents and purposes, assuming 100% weight retention, the size of the hole made by a handgun bullet in flexible tissues is the size of the recovered projectile.