I own a G3, have played tournies and trainings with it, I love the thing. It has a fully legal board if you get the proper G3, I don't know about the IQ or Nano, both of which can be confused for the G3. It can shoot up to 25bps max semi, but you can only cap it to semi 15 with the stock board. It will stay at 12 for Millenium mode.
I'll give you an honest pros and cons here:
PROS:
Lighter than a Mini stock (1.86lbs with barrel, battery, ASA) with better feel in my opinion since it has a normal reg
About 7 Orings TOTAL in the bolt, that's including the back cap Orings and the bumper oring, so easy to maintain.
Most accurate stock marker I've ever shot, even with the stock barrel.
Amazing RAPS on/off ASA, flip the lever on & off.
Fully tournament legal board for 08, dipswitches to turn everything on/off including dwell and ramping, uncapped max ROF 25bps, NPPL (semi), NXL, PSP and Millenium modes all up to date including new Millenium 12 bps ramp limit.
Great stock reg, it's been consistently +/-5 fps, and sometimes as good as +/-1.
Comfortable grips with special cuts to improve handling.
Quite efficient for a spool valve marker.
Medium sound signature, not as quiet as PMs or DMs, but close.
Comes with spare Oring kit.
Great grooved clamping feedneck, grips tightly onto loaders.
Very well balanced, not tank heavy, not barrel heavy.
CONS:
Alot of side to side play in the trigger, may bother some.
If you are VERY particular with anodising and milling, there may be some very very slight anno markings, this has been commented on by many owners, but the markings are very very small, barely noticeable.
Reg is prone to failure if you overtighten, but so are many other regs.
Board has limited settings for dwell, ABS etc, but there is a new board available with more functions than you can shake a stick at, from APE 31st August that will not be very expensive, probably less than 100 USD.
The trigger stop screw can bite into the anno just behind it if you are heavy on the trigger like I am, creates a tiny tiny mark, but just so you know.
Ribbon eyes, if you aren't careful you can tear them.
NOT LUBED if new from the factory, you must lube everything including the reg.
It's a US company so repairs may be difficult, but nothings gone wrong with mine yet.
Hard to find.
My opinion? I'm a bit of an amateur marker whore
and I've owned and shot loads of markers, I'd go as far as to say this is the best spool-valve marker out there that I know of
Most of the time my Angel takes a back seat to this little thing, and I suspect even when I get an A1 Fly, the same may be true, lol.. Love it, get it and you will too.