I've only used an airbrush for a few hours but it was all testing aspects I thought I would use.
So I bought a kit with some master brushes and added an Iwata Eclipse. I will be painting 3D prints mainly as well as motorcycle fairings and parts once the skills and experience scale is much higher.
My compressor can run two airbrushes and tested that successfully. I thought this would be a good option to run two colors without having to flush brushes till the session is done. This manifold worked perfectly.
Zero leaks anywhere. Later I will add Teflon tape because that's what I do with threads but wanted to test it without first. The lines are not the best ever but they are not bottom of the line so time will tell how they hold up.
I used the screw mount to secure it to my paint station. Very solid. It holds the gravity airbrushes fairly solidly. Could be deeper in my opinion. Super light siphon feed brushes don't seem to fit. The unit will swivel when inserting brushes or pulling the lines a bit. I guess that allows movement with mounting options or some sort of hose saver so you don't break lines? In my case I didn't need this so I drilled a small divot in the post, super glued a small BB and used a file to add a channel to stop rotation just enough to stay in place unless you pull with a bit more power.
Later I plan to 3D print some different brush holders.
So far I am very happy with the unit. I'll update my review after a few months of long term use.

holders are plastic but otherwise pretty good

The only thing I could find wrong with this is that the tiny little labels on the valve heads are backward... they indicate clockwise (open) and anticlockwise (close)... when the reality is the reverse of that. This has zero impact on actual function but is a momentary confusion.

There is a small hose loom that comes with it that is intended to mount below the air inlet port.
When a pretty much normal hose with a crimped ferral is used, the ferral prevents the hose from mounting correctly... The hose loom has zero function and can just be tossed out.
If you really just can't live without having all 5 hoses draping pretty from one point, you could use a plastic cable tie to accomplish the same result.

All of the important bits work and they work very very nicely.

The aesthetic appearance is outstanding.
The manifold block is clean and free of burrs and the valves function smoothly.

The clips hold an airbrush very nicely and they allow for any airbrush of which I'm aware, with either gravity fed or siphon fed cups.

It could possibly have a problem with very large siphon feed bottles due to limited clearance between the airbrush holders and the manifold block, but the 1.5 ounce bottle works reasonably well.

Was looking for something to hold my airbrushes, organizationally. Seems sturdy. Good aesthetic. It'll do! I'm not concerned about the air suction/pressure.

Works as described, for the most part. Does not accommodate airguns (Grex and Tamiya). Holder is too narrow for these. Standard airbrush seems to work fine with the holder. The adjustments for airflow is a nice feature, although a bit finicky, you can get the flow to your taste and it will remain consistent. Overall, a good product. -hjp