New barrel, preferably an ID matching system. Halo or Evolution 2 hopper.
Fast, accurate, durable, trigger magnets (hey everyones using them now)
heavy, costly (what high end isnt though), stupid barrel nubbins, on/ off pin.
This is the greatest gun out there. Well except for maybe the Xmag. Its insanely fast. I cant even get the thing to put out the RoF its capable of. It gets 750 shots out of a 68ci 3000psi tank which isnt horrible. To all those out there that say it chops, get a real hopper! Try the halo or Evo 2. If you had the money for the gun you should of had the money for the hopper too. I didnt chop much before but I never chop with my Evo 2 now. Dumped 1500 rounds through the gun 2 days ago and didnt even get a barrel break. Did I happen to mention that was even after the steel nubbin broke in my barrel. Oh and no lvl ten bolt in mine either. It even shot Zap paint sold at a huge chain sporting goods store. Not to mention some Brass Eagle paint that had to be cleaned because of a bunch of broken balls in the bag. The only thing I really dont like is the wieght, but what yah going to do, and the activation magnet screw in the trigger stripps out very easily. Oh one last thing electronics stores sell wall chargers for like 20 bucks. So while your out getting your new hopper so no one has to listen to you whine about chopping any more pick one of those up too.
Over all a beautiful marker. Think I'll have to get the c&c body when it becomes more available, but thats just out of vanity. Also because I hate chrome. Other than that save yoru pennies kiddies its worth it.