I have the Kessil 160 and the AI Prime HD
The difference is the Kessil does not need a controller, it is very easy to tell exactly where you are at, turn the knobs for your preference. There is lots of skimmer, but I like the color blending of the AI Prime HD looks much better. The Kessil is a very wide projection of light the AI Prime is not.
The AI prime needs a controller IE has too. Using with my non updated Samsung S-3 it is a pain in the butt to program, I really do not know where I am with this light, yeah I am not tech savvy, I've had it at 100% over a QT and caused a massive algae bloom so bad it killed the Aptisa LOL.
Get the HD model if you do because you can copy the AB+ exactly and that is a proven spectrum that works.