I thought this might make for some interesting discussion, when it comes to cleaning carpets, do you prefer automatic or manual height adjustment? Certainly manual adjustment gives you much more control. I've found that some automatic height heads will float in order to adjust to different carpets, but many are just set to one height, which is probably in the mid range. If you use manual height adjustment, what do you think is the best setting? I would think you would want to set it as low as you can while still easy to push. On some power nozzles such as the Sebo, there is a light that will indicate when your brush is too high, do you rely on this or use your own judgement? Again, I would think going as low as possible while still being easy to move would be a good setting. On power nozzles such as the Aerus, it's automatic, but they claim it will clean all carpets well, not sure how true that is though.