Quinn,
I don't run skimmers, refugs or sumps on any of my three reefs, only use mechanical filtration. Works pretty well, only the media requires at least weekly cleaning depending on the bioload.
Our first reef, a 75g started up in 1998, used both a skimmer and mechanical filtration. Skimmer skimmed well, except for the occasional overflow
. IME, skimmers don't pull out the larger particulate matter which mechanical filtration does best. Again, depending on bioload, media needs to be cleaned weekly even with a skimmer, which also benefits from weekly cleaning, IME.
I dunno, but the combo of skimmer and mechanical filtration, without refugs and sumps, is a useful, two fisted approach to crud removal and nitrate reduction. JME, though....