Dan, I agree with you....the Miele S500 series was their best models. However, I personally feel that the best Miele models in this series comes a couple of years later, in 2004 when the Vortex motor was introduced. I have a 2002 Miele S538 Monte Verde, which would be the model just below the Aluminum, which has the 1100w double-stage motor, & a 2004 Miele Red Velvet with the 1200w Vortex motor. Sure, the Monte Verde cleans well & has plenty of power....but the Red Velvet just feels like it leaves the rug cleaner, even when the 236 powerhead is used. I think in 2004, they finally had everything in their product perfected.
Rob