Using a 3rd party GC2 gun is not a great solution for me. I have tried a lot and none are anywhere near as good as the official Namco ones. Their accuracy sucks. Poor lenses and badly designed electronics.
My experience has been that the Guncon 2 works well in Windows if used with real light gun games. From what I have read, a lot of the issues people have had is when trying to use them with games that never used a light gun like Terminator 2.
IMO, the best approach is to use an official GC2 or an Act Labs gun for real light gun games like Time Crisis or Op Wolf. Then pick up a directional gun (with an Apac) for games like T2 and Op Thunderbolt etc. An Aimtrak is probably the only option currently for CCD gun games. That is, arcade guns that used an IR camera with sensors mounted around the screen. That is.... unless someone feels like finishing the GC3 PC drivers...
I think it is worth using a real light gun even if it means sticking to an older 32 bit mame for gun games. It is not like we have seen any real progress for light gun games with later versions of Mame.
I've had different experience, the Guncon2 that i'm using has excellent accuracy and works reliably, it only needed a bit of manual tweaking in the guncon control panel, afterwards it was spot on, furthermore it has served me for many years without failing.
The official Guncon2 won't work perfectly in any situation, even in xp 32. Smog's drivers won't work correctly with the gun due to the rolling x issue and Wingun also has some issues with it, so the only real option to use a Guncon2 is a 3rd party. Perhaps it's possible to use the first guncon with a converter.
Personally, i think the only thing needed is some sort of an application or something to make the screen flash white when pulling the trigger or clicking left mouse button.
Just to clarify about wingun, i've included a portion of the readme file:
"--Troubleshooting/Known problems:--
The Rolling X problem is not fully fixable, we do not have all the information we need. Because of this, support for guns in Rolling X mode is a hack. The user MUST do the following with guns in Rolling X mode:
When bringing the gun back onscreen from being offscreen, it must be done on the left or right side of the display. It cannot be on the top or bottom of the display.
The gun should not be jerked from side to side, smooth motions work best.
Guns in rolling x mode will always experience these problems:
After pointing to a black or dark spot for a second or so, the gun may skip to the other side of the screen. Simply wave it offscreen then back on, or across the center in order to regain correct positioning.
The gun cannot be moved across a dark center screen. If this situation occurs, you will need to bring the gun to the section you need to point at from the left/right edge (whichever is closer).
Some guns (specifically the Namco official one) will jump to the center of the screen occasionally. This can cause the gun to move to the wrong side of the screen the same way a black spot can. I have done all I can to fix this, the gun is returning an incorrect position when it is in a darker but not black area.
For all guns with the rolling x problem, you might have best luck shooting targets on the egdes of the screen by bringing the gun onscreen from the closest left/right edge."