I've been using the free zoneedit on one of my domains for the last 4 years. Everything works perfectly and I havn't had a single problem. I don't think I've even logged in to their control panel in the last 3 years
The dns servers at zoneedit (ns1 & ns14 were the ones that were down) are now back up. They were down almost a day and a half. That is the only problem I have had with them in approximately six months. As they suggested, a third dns server would have prevented this outage from being a problem.
I have purchased a small business account at dnsmadeeasy. I find their "vanity name server" service at no extra cost appealing.
I have yet to set up any domains with dnsmadeeasy.