I was wondering if recirculating skimmers are sensitive to water level changes or if you forget to turn of while feeding do they go crazy like a in sump model would. Do they over flow like a in sump model.

I never turn mine off while feeding. The water level is controlled by the feed pump. The only time I have a problem with the water level in the skimmer is if something is clogging the feed pump, otherwise it stays exactly where I set it.

That's what I like to hear. I am thanking about getting one.

Go for a recirculating....lot less hassle of making sure your water levels are right. I would not trade mine for the world. Also it allows for more space in your sump for whatever you might be putting in it.