Guys, look back at my first post - we have "descaled" over and over and over. Tried the "coffee pot cleaner" packets (probably the mentioned Urnex), vinegar (exactly in accordance with Keurig's instructions), then straight, full-strength vinegar (after emptying out as much as possible from the heating tank), and finally CLR. With the CLR, I removed several of the internal hose clamps, totally emptied the heater tanks, and then syringed it directly into and through every passageway. And let it "soak" for 30 minutes.
It ran terrific for about 3-4 quarts of plain water while rinsing and flushing, and then immediately clogged again.
I'm convinced I need some design OTHER than Keurig's. But we are firmly in the "K-cup" world. They just suit our usage patterns too well.
We'll see how the Bunn does. I'm very hopeful. It sounds like a terrific machine, even if it DOES still have pumps, etc. that will need the vinegar descaling.