OHH, and if you are anything like me, I like to look at readings in the way that I am used to. In the Apex Fusion you have to look at the salinity in ppm, while in the GHL Control panel you can convert that to Specific Gravity, which is what most of us are used to, aka refractometer. I have to give GHL a .5 for this small luxury.
Apex 1 GHL 2
Apex 1 GHL 2