What a marvel! I've had one for approximately 5,431+120 C14 years and probably run an Olympic sized swimming pool of water through it. And it just keeps working. Had to replace the pitcher once because the handle broke, but otherwise, it's a superb appliance, if you like iced tea. And I do. I drink it practically every morning, winter or summer (probably that southern 1/2 of my genome). And only Luzianne tea mind you, because it's the only stuff I've found that doesn't turn all cloudy. Back when we used to vacation with my dad's kin in Alabama nearly every summer, we'd get served Luzianne all the time so it brings back good memories as well.
I won't say it's the best design in the world. At least the older versions have a nasty tendency to leak water when in operation. The unit itself doesn't leak, but it's got a funny way of getting the water from the heating unit into the pitcher that lends itself to water not hitting the pitcher. So a towel is always needed. Still, the sucker just keeps going and going. Probably a very simple, bullet-proof design.
Having said all this, I can probably expect it to conk out any day now. . . .