"enough" is relative. There are those that think compact fluorescent clip-ons from Home Depot are enough. Some think Kessil H80 are enough. I've not seen many think that the H380 isn't enough, although they have the H1200 for those that may need it.
For me, the H380 was way overkill for my small reefer 250 sump (well stocked, well fed, well skimmed tank, with 5 chromis, 2 clowns, 1 flame hawk, 1 med yellow tang and a RO regal 150sss skimmer). I had to shade to restrict the coverage and it was stripping out nutrients too fast so I had to limit the photoperiod to just 6 hours or so, and I was still running at 0 for Nitrates and Phosphates, so I started dosing them.
The H160 for me seems to be on the high side of "enough". My photoperiod is up to 12 hours with the first and last hour being faded in and out, which results in a smoother PH curve on my APEX. I'm still having to dose Nitrates and Phosphates in my ATO water, so I could reduce the intensity, but things seem to be happy.
Would the H80 have been enough for me? Maybe. But for me, the H160 gives me the flexibility to increase and decrease period and intensity at will and has a bit of headroom left if I need it.