I bought the trainer to use with a track bike and have used it nearly every day for the past three months. The original flywheel and its replacement were defective--usable but very noisy. Cycleops replaced both promptly with no questions and sent me a return authorization so I could ship back the defective units at their expense. The third flywheel seems to be the charm; it is quiet and so far works perfectly.
The Magneto functions exactly as its designers intended by creating a little more resistance (but not a lot) as you increase pedaling tempo. The properly working flywheel is quieter than the electric fan I use to cool myself during a workout. It is a fairly basic and relatively unsophisticated machine and does what I wanted. From that standpoint, and because the manufacturer stands behind its product, it earns a five star rating.