I've seen that video and it is accurate, however he was comparing the component output of the Alibox to the RGB output of the OMVS. The RGB output in the cbox is considerably better, if not quite perfect. On my CRT I use a HD Retrovision cable to get component out of it and the transcoder in that is significantly better the CMVS's built in component. It's not absolutely perfect, and those that measure video quality with an oscilloscope should probably look elsewhere. Compared to my other Neo systems (which I can assure you have good RGB) using the same cables video quality is comparable across all of them.
I also wonder if they've revised the audio circuit, the audio out of it is as good as any of my cart systems and better than some. I haven't traced the circuit to see exactly what they do with it but it pulls form three points on the PCB and not the jamma harness, so it seems to be a proper mod. The volume levels are comparable to my CD systems' RCA outputs, which I would use as a reference since they are only SNK made systems with proper line level stereo out.
I'd still recommend most people get an OMVS these days since I don't think JNX is taking new orders right now. It's better built, uses a more reliable MVS board as its base, and uses higher quality internal components. I purely bought this for the shell, fully expecting to gut it and redo everything on the inside and pleasantly surprised that it didn't need it. Next I'm gonna build a CMVS from scratch like it was 2007.