Ultimately, we can throw numbers around all day, but what really matters is what gets the dirt out of the carpet. Personally, I don't feel the Kirby is the most effective at removing things like sand, the nozzle is too wide and dilutes the machines power compared to something like a Royal with a narrower nozzle, also the brush isn't aggressive enough for my liking. I feel a Convertible or a F&G Eureka will get better results. The Miele works well, cleans well, and I feel is more aggressive on the carpet. Ultimately, I don't use a Miele or Kirby as my primary vacuum, my preference tends to be Rainbows, Riccar Radiance, Riccar central vac, that sort of thing. Machines with high airflow and aggressive agitation (not carpet shredders though).