Things I liked:I should have bought this product years ago. The piston delivers better shot to shot cosistency over the spring system. I cant say enough about Pyramid Air, this purchase was the fastest turn around ever. Im very satisfied with Pyramid Air and my newly installed Nitro Piston. Things I would have changed:Cant come up with anything What others should know:This product is worth every penny, a Nitro Piston should be your first upgrade.