I don't have any experience with the Vertex and am having trouble finding any information on it at all. I've used black box LED lights, but not the Mars Aqua specifically. Most black boxes are about the same though. Since most recent web pages I can find about the Vertex are from 2012-2013, I'm inferring that it's a very old fixture. I would personally probably choose the Mars Aqua for several reasons.
First, the Vertex is older and used. Since it's hard to find any information at all about the Vertex, I'd imagine finding replacement parts would be even more difficult. Black boxes, while they typically don't come with manufacturer support, usually have at least a 1-year warranty. After that, many people have modified or repaired black boxes with commodity parts. So if the black box fails, at least you can fix it. Also, if a black box fails and you can't fix it, you just replace that box for a hundred dollars or so. If the Vertex fails and you can't fix it, then you have to replace the entire thing for the entire purchase price. Which would be much more costly.
The second reason I would choose the black box is the LED quality. While I don't mean to say that black boxes are the pinnacle of LED reef lighting technology, the Vertex, being old and primitive, will likely not provide the best spectrum and light color. From what I can find,
the Vertex has only warm white, blue and royal blue LEDs. I have an old AI Sol that has the same light layout, and while the fixture is fine for QT tanks, only having three LED colors definitely leaves something to be desired with regards to the color the light produces. Back in 2012 - 2013, white/blue/royal blue was the standard and it worked, but I believe even a cheap black box fixture, like the Mars Aqua, will provide much better color than something like the Vertex. I have a Viparspectra black box, and the color is leaps and bounds ahead of what my old AI Sol produces.