That again boils down to personal choices as to how you want your biological filtration to be accomplished.
There are many ways to achieve it so it's just a case of picking what suits your pocket book and your own satisfaction.
I don't use a refugium or HOB filters, although I did use a HOB on one tank for a while but strictly as a water mover as I was short on power heads at the time.
I prefer to work with a sump, having my live rock as the filter but in the sump so I can see more of the seahorses.
While many like live macro for decor and hitching, I choose artificial decor/hitches so that I use minimal lighting to help keep temperatures down. I can't afford chillers on all the tanks I have.