Stock setting compared to PGP stock setting:
Longer Barrel
Longer Pump Arm makes pumping easier
Easier to take out bolt
Easier to adjust velocity (you have to remove the bolt first)
Holds 5 paintballs more than the PGP
Longer CO2 Knob allows for better grip
More weight is put forward because of the longer barrel, it makes it feel a little unbalanced.
Make sure that you clean out the paint (the one Sheridan used to paint the P68SC black) that is left inside the barrel. This gives the gun better range and less of a chance for it to chop paintballs.
Also break in the pump arm so that it isn't still when you use it.. It doesn't hurt to grease up the pump arm either.
Paint rubs off of it after awhile so becareful when cleaning it after a game.
Most aftermarket parts for the PGP are compatible w/the P68SC.
Conclusion:
Like I said, this is basically a upgraded version of the PGP. I wish that these were still being made today.