As you probably already know, I have a ViparSpectra and am partial to that light.
One thing I would consider is that it looks like the Mars Aqua only has adjustable knobs for setting intensity. I have another black box (a Galaxy Hydro) that has the knobs too, and it's more difficult to set intensity than it is to choose an exact percentage on the ViparSpectra. While I don't really need the built-in timer of the ViparSpectra, I do like the ability to pick an exact intensity and move it up or down by percentage point. The Galaxy Hydro in particular seems to offer very poor control from 0% to 10%. You basically have off (0% intensity) then 10% intensity, and not much in between. The knobs just seem much more difficult to adjust too. It's easier to look at a display and choose an exact percentage than it is trying to line up the little line on the knob with the % sticker on the light (at least I feel that way).
It's possible the Mars Aqua uses better potentiometers in their lights than the Galaxy Hydro. It also looks like the LED layout is pretty similar between these two lights, so it's unlikely that either produces significantly more or better light than the other. Just something I would personally consider.