Got my unit through this week too. Good ol' Covid ensured that the journey from China to the UK was long and treacherous but I'm glad it made it here in one piece!
While I am still very new to the world of arcade collecting and ostensibly, superguns, FWIW I can't heap enough praise upon the good work Axun has done with his JVS/Jamma Controlbox and of course to Drfunk2k for being so diligent, helpful and pleasant in helping to facilitate my order so quickly and to ensure I had all the right bits to get started.
As you all can see from my setup, space is tight and so when I came across the JJ/CBox I knew I had to snap one up pronto... I have never been a fan of the bare bones affair of most other supergun solutions with the need for external power supplies and the requisite viper's nest of wires that comes with all of that - way too much hassle (or I'm just too lazy, let's be honest) and mess which I'm not a fan of.
I currently own 3 PCBs - namely R-Type II, R-Type Leo and a CPS3 (with all the Darksoft upgrades, etc) which all run perfectly without a hitch. It's dead easy to switch between boards and flick a switch here or there to adjust things such as the brightness output using the 75 and 150ohm switches on the rear of the unit, and of course there are the 5v and 3v voltage pots that are easy to tweak in conjunction with the voltmeter JAMMA extender cable I bought with it.
Control-wise I tend to just use a Neo Geo CD pad as my "daily driver" for casual play, but I have also tried the Saturn ports using both the standard wired pads as well as iam8bit's wireless Saturn pads which play just fine with the JJ/CBox. I have also tried a PS2 Neo Geo CD Pad with a PSX2NeoGeo Adapter V3 from Retroelectronik and again, no problems with either 3 or 6 button play. Video-wise, I am running the unit using the 8-pin din to European RGB Scart to my Sony PVM which is also daisy-chained to an XRGB Mini and again, flawless performance in both scenarios.
I feel funny as a complete newcomer to this very specialised corner of retro games collecting and preservation going all out on what I would deem a very high-end and "pro" level of equipment when I haven't directly experienced anything else before when it comes to running arcade hardware at home, but I had always found it quite a daunting prospect to jump into. When I saw the Axun's JJ/CBox I felt it was the ideal unit to enable me to dip my toe into this new world and I'm so glad I did. It's a pleasure and an honour to be one of the few who owns one of these finely crafted units and I think it's fair to say I've got the arcade collecting bug good and proper now
Edit: And if anyone has any questions, I'm happy to answer them as best as I can! Will add any further bits to this little review if I think of them.
Edit 2: I would like to add that I have found the Saturn ports to be on the tight side - this is not to nitpick at all because I really do think this is a superb piece of kit, but it did give me issues at first. I can get my pads to work fine if I don't push them in all the way, but otherwise I may find that inputs are stuck or the pad simply doesn't respond at all. Assuming that this is the same across all units, leaving the pad connector out by about 5mm seems to ensure it works just fine though.