I just got one.
The manual (the first thing everyone looks at) is among the best I have seen. The diagrams are clear, the descriptions are cogent, and the instruction is helpful and simple.
The Matrix is a very stable shooter, with little noticeable kick. It is hard to tell anything is happening while you rip on it, unless you watch the rope of paint projected in front of you. In addition to little or no kinesthetic disturbance, there is very little noise. I have been lost frequently by the other team, despite being active in moving and shooting.
I have not chopped paint in the four cases I have put through it, though I experienced barrel breaks with some really delicate Draxxus. The eye seems to work very reliably. When it is on, the bolt will not close at all unless paint is detected. I don't know how well it sees through broken paint- the situation hasn't come up yet.
The stock barrel is good- I have used it with good results shooting Zap, Draxxus, and Kick'n, though I broke some very brittle Inferno. This batch of Inferno fared dramatically worse in other guns, so I am not really let down. The shoot through was excellent.
Efficiency was terrible. I shot five pods and a Halo on a Crossfire 72 CU 4500 psi tank. I don't know the translation to liters, but that's a bit bigger than the middle sized tank, not as big as the big size. Anyway, that was disappointing, but not unexpected. Matrices have the reputation for being gas hogs, and experience bears it out.
The regulators (very dildo-ish) were really consistent, unusually so. I experienced a range of about 1 FPS both ways! There was the occasional odd ball jump of 8 fps or so, but I blame that on odd balls.
The maintainence seems pretty straightforward- check the o rings, grease the hell out of most of them, and screw it back together.
The trigger was not especially to my liking at first- heavily sprung with a lot of excess travel. The trigger set screw for limiting back ward travel (in the stock trigger) can only be adjusted by removing the grip frame, so I took it out and turned it upside down. Now I could adjust it with a round tip allen key. The forward travel screw was more accessible. Once I set these to limit travel to taste, I still found the trigger stiff. I took out the spring and used the micro switch to return the trigger. I cannot make it bounce this way, but it is much easier to shoot quickly.
The feature set is similar to any LCD Matrix. Included are a timer, a BPS counter, a shot counter, a "trip" shot counter, a thermometer, a battery gauge, and a vibration and/ or tone alarm for the timer. Plenty for me.
Once I got the trigger set up, this became an amazingly easy gun to play with. I stopped thinking about the marker, and started thinking about shooting people in the butt. They let me. Whee!