One way to think about the newer, bigger, sewing machines, is that they are computers. Circuit boards are warrantied for about 5 years (you may want to check that on the Dreamweaver and Crescendo). When one of those goes out, it's a major expense. That might be when you'd want to up-grade--as with any computer. There's also software up-dates on some machines--just like a computer. The older mechanical machines will run forever if taken care of. Not so much with the computerized models.