The G&P I.A. grip is an ergonomic grip with several improvements over the standard milspec grip. The most obvious are the grooves for the fingers with textured patterns at the bottom but less obvious is the increased bulk at the rear of the grip to conform to your hand and the more vertical sweep for the hand between your thumb and index finger.
The G&P I.A. grip for the AEG has lines to simulate interchangeable panels (not actually interchangeable) on where the real steel version would. In this instance, the panels cannot be made removable due to the need to house a motor for the version 2 gearbox.