Stock gun right out of package. Nothing added, nothing subtracted.
Maybe a bolt upgrade, but only if you are going to use this as a primary marker in games, seeing as it's ok as-is for a sidearm. You can feasibly put an E-Force trigger on it if you want to emulate a Glock 19 or something, but I wouldn't recommend that considering the magazine capacity.
Decent recoil control
Easy to field-strip
Inconsistent CO2 use
Ammo capacity (this shouldn't be a problem for it's use.)
i would like to stress the fact that you should keep the seals and O-Rings well lubricated on this marker. If not it tends to leak. Aside from that, it's fairly light and deceptively accurate for it's barrel length. It makes a nice sidearm, but unless you're good it should be only that.
I would suggest this to anyone who would like a sidearm to accompany them in woodsball, it takes a little getting used to but it's nice. I would like to give a few warnings and considerations...
1 Keep it lubricated, especially the seals.
2 You're better off at lower velocity, seeing as the higher speeds tend to chew through air too quickly and give you a crap trade-off.
3 Practice reloading it for at least fifteen minutes before using it in a game. You'll never regret it.
4 If you feel the need to upgrade this, then you probably never needed it.