The stock ICS motor is a high-torque but low ROF. In essence, just about the only thing you *really* need to do to an ICS is the shaving of the 2nd tooth. It's not something I consider hard: after all ICS ships their guns with an instruction CD (!). Plus with a split gearbox you don't have the "parts exploding everywhere" issue with most mechboxes.
tbqh though, is there really any gun, other than a TM, that doesn't require some sort of preliminary examination by a gun-doc before use?