I think that there are multiple correct answers about how to set up a tank. Skimmers remove roughly 20-35% of dissolved organics, so if you are running a skimmerless system your reactor/nutrient export needs to be 20-35% better (or more).
http://www.advancedaquarist.com/2010/1/aafeature talks about DOC removal by skimmers.
I ran a skimmerless system about 20 years ago (Caulerpa driven, which worked but smothered my corals), and am running a different macroalgae-filtered skimmerless tank today (which I feel is much more well thought out). I decided to take the (not running but still in sump in case I needed it) skimmer and remove it. I then replaced that space with a refugium. BRS ran some experiments on lowering nitrate and phosphate with chaeto, which I thought were pretty compelling -
http://www.bulkreefsupply.com/video...-best-refugium-light-and-what-is-coming-next/
My tank is a Red Sea Reefer 170, 34 gallon display, 9 gallon sump. Dragon's breath and gracilaria in the main tank, dragon's breath and chaeto in the sump. Sump refugium lit by a 24w PAR38 grow bulb. As of today, nitrates < 1 and phosphates < 0.05 (Elos kits at LFS). Having said that, I feed about a quarter to a third cube of food with 2 small fish and a cleaner shrimp. I also add Reef Chili twice weekly (the small scoop). I do run activated charcoal.
I chose a skimmerless system as I wanted to maximize pod production via a refugium, and I've found a refugium with macroalgae to be a very low maintenance solution (pull out macroalgae and either sell it, trade it, or trash it).