If you are doing just a kessil with no t5's etc, then the hydra 52hd. You'll love the ease of use and customization way more than the kessil, and more power imo.
Don't spend money twice. If you go kessil, you'll need some back up light. It's a beautiful effect but having more than you need is always better imho. Also, if you ever do go hybrid, which you don't need to necessarily with the hydras, you can do that with an easier form factor, oh and no added controller needed. It's a scam I tell ya. If you want to see what hydras do on their own, go check out Junio Melo's TOTM. I use Hydra 52 HDs too so I'm biased but practical.
I have numerous tanks running on Hydra 52s. All corals (soft, LPS, SPS) seem to do really well when placed properly and the spectrum is set up appropriately.
You have to be careful to avoid the temptation to play with it too much. It’s so easy to adjust that you can get into a mode of messing with it all the time and freaking the corals out.