I think the responses you get might depend on what type of coral you plan on keeping. I suppose the best strategy is to buy something powerful enough that you wouldn't have to upgrade if you decided to go full or significant SPS. Personally, I love the look of a Kessil light more than any other LED I've tried including various black boxes, AI Hydra, or Radions. It could just be coincidence, but when I switched to Kessil my corals started to grow much more quickly and I've had to almost double my ALK and Calcium dose in the last few months. Two AP9X would be amazing on your tank for SPS and one would work for a mixed reef with SPS in the middle and LPS/softies around the perimeter. You could also consider adding one and keep your T5 for more coverage while still adding a bit of that Kessil shimmer to the flat light that T5's put out. Again, this is all going to be dependent on your goals for the tank, budget, and what appeals to you visually as an individual.
Edited to second the post above about the 360X's. You could use two and spread them further apart, but I think you also would have to get a wifi dongle or spectral controller to use the Kessil app.
