.2 to .5 second a lap... uh, I doubt it.
For ease of use and quality, I like that list, but I put the Serpent RCC shocks above all of those. With the Serpent shock tool, they are the easiest shock to build I have ever touched—and I've used all three of those others on that list.
But there is no way that TRF shocks will improve the car .2 seconds a lap over the stock Mi3 shocks—which are just as good, if not better than the Tamiyas.
You may be feeling a difference in piston hole size, rebound or bladder material, shock oil or some other difference, but there is no way that apples to apples there is a time difference like that on track.