Sheridan tried to improve upon the perfect original. Though it may look cool at first glance, its really not. Velocity adjuster and quick change are something that can be added for little money on a stock PGP, and the barrel extension isnt needed and doesnt really add accuracy. It aslo adds length, and I bought my original PGP for its shortness. Accuracy is an acuired skill, not something you can add as an accesorie.
Plastic loader is horable, it only messes up the feed and breaks off.
Id drop this idea and buy the original, if you can find it. Or try to buy one used. PGPs dont break, its that simple. I rarely have breaks and it shoots rather consistent, and will reach a good velocity. Easy to strip down and clean.