I would definitely question their high ratings on the Kenmore products. My ex-wife and I bought one new in 2002 and was the sorriest piece of plastic junk I've ever seen. Sure, it picked up cat fur great, but it was simply not up to the task of vacuuming the house 3-4 times a week. Sears had to repair plastic hose connectors twice under warranty and when she and I split up, it was held together with nylon cable ties. As others have pointed out, CR's testing is pretty superficial and involves little or any real world testing for durability.
As for me, I'll stick with my metal monsters, thank you very much.