I've been using Whiteside bits for at least 10 years. I'm not technically oriented enough to tell you all the reasons why, but they cut better right out of the box than anything else I've ever tried. And they just seem to hold an edge forever. I probably have 30 Whiteside bits, and I haven't worn one out yet.
Far as I know, Whiteside bits aren't available in brick and mortar stores in my neck of the woods. If I'm in the middle of a project, and find I've just gotta have some particular bit that I don't already own, I might run out and buy some other brand. But anytime I see the need coming, I order Whiteside online. If I had a local vendor who sold them, I'd support that resource.
“We should be careful to get out of an experience only the wisdom that is in it and stop there lest we be like the cat that sits down on a hot stove lid. She will never sit down on a hot stove lid again and that is well but also she will never sit down on a cold one anymore.” - Mark Twain