RGM Vortech (mine) boosts 0.44 bar @ Nelspruit altitude.
My understanding is that the Sprintex boosts 0.6 to 0.8 bar depending on pulley, so greater output would be expected.
IMO the equation is simple:
+boost = +power -reliability, and you decide what level of risk you're prepared to take.
After having been boosted @ 0.44 for over a year, 25000+kms, and almost 500 racetrack laps, do I want more?
Nope, I'm very happy as is.
For minimal cost I could fit a smaller pulley, but I've decided not to do that.