I have two PST G2s. A 3-15ffp, and 1-6sfp.
My neighbor (against my advice...) got a 5-25? diamondback. Anyway, it was readily apparent just looking at the stop sign down the street the glass is half of the gen2s. It's usable up to about 16x, but the lack of quality is shown at higher mags. The extra money was easily justified in use even at 400yds. I didn't screw with the turrets at all, but as expected we had no problem getting it zeroed or holding zero during the day, about 100 rds of 6.5jesusmoor.
He has since seen the light and picked up a bergara to replace the axis, and a gen2 25x to replace the diamondback.
On the same note. The 25x ffp, loses the edges of the reticle at 20+, kind of bad at 25x. Although if you're using 25x, you probably need to dial anyway.