My testing and shooting is with handloads. Coated lead, so not ideal for for 25yd groups. With various brands, bullet weights, and loads I couldn't do better than 3-4" rested groups, almost always with a flyer or two. Many times I would get 5-6" groups, very frustrating.
With the PM barrel, rested groups are down in the 1.5" range with pretty much every load/bullet I've tried. No doubt I could do better with jacketed bullets.
If your P10 shoots poor groups with the OEM barrel, buy a PM barrel with confidence. If your OEM barrel yields 1" groups, what more do you want from a $400 plastic gun?