I went skimmerless when I was out of town working and had people watching my tank. Since it was a HOB I did not want to risk overflow.
Anyways, the tank was without a skimmer for 3 months, did fine, even with heavy feedings.
I had no sump or anything, either. What kept things in control was the dictyota algae in my tank, that stuff consumed extra nutrients like there was no tomorrow. So, whenever I came home I would just take out hand fulls and things would be fine. The only risk was smother corals.
So, if you have a sump or nice place to go macroaglae then going skimmerless should be no problem. I swear this algae is more efficient than any that I have ever seen.