Holley Sniper runs at 58 psi while Holley MPFI runs at 43 psi. But the Sniper injectors fire into an annular ring and then the fuel dribbles out of there. So it isn't really injecting directly into the air. I have no idea how a Sniper compares to a carb in terms of atomization since the dynamics are very different. The average guy has no way to measure this stuff.