Mine lasted for three years of heavy use, and was just replaced before the end of my three year warranty. It took seven hours for the experienced tech to do the work I needed, but only about five or so were related to the belt. I also had my service station and spittoon replaced, which were entirely full of ink. The old service station weighed about five pounds more than the new one, and the technician said that it was the heaviest that he had ever replaced, all due to the ink inside. My belt was separating lengthwise and throwing off small bits of rubber. It sounds like a new printer now, and I no longer need to watch it print to blow off the black bits of rubber before the ink hits the paper or wipe down the service station to avoid random drops of ink falling on my prints.
BTW: The engineering behind the belt change process is as lame as it gets. You can access both ends of the belt, but still need to tear down the whole printer to change it. It is like needing to pull the engine of a car to change the oil filter. There's a lot of great engineering in these printers, as well as some really silly details as well.