Yes, around 2000 fps is the threshold where you start to get permanent tissue damage in the temporary stretch cavity. Problem with handguns is in order to get this velocity you have to use such a small and light bullet it (generally) will neither penetrate enough or create that big of a wound anyway.
The 5.7 out of a 16" barrel is about like a 5.56 out of a SBR so it is doing decent.
In my googling of the 5.7 out of a pistol it looks like most shots I see, penetration is in the 9" range, but a few are 12-13" A 12-13" penetrating load would be a solid choice. The 5.7 seems to make the concept work for close in work, the stuff of pistols and PDWs, add any distance and the round quickly gets below 2000 fps and you just get a .22 hole.
There is a photo on the FiveSevenforum where a 22lb pork shoulder was shot with a 5.7 pistol and it graphically demonstrates what 2000+ fps velocity gets you, a 4" wide permanent wound cavity. It penetrated 9", but that is in solid muscle, so in gel it would have went further.
I don't own a 5.7 or care about them one way or the other, but it is an easily researched way to see the light/fast (~2000 fps) concept in action.