The Aerus is much lighter than the Rainbow if you want a machine that is easy to carry and use. I have a Rainbow E2 which I bought new, it is in the back of my closet unused. We stopped using it because we found it to be very heavy and clumsy to use and move around or carry upstairs. I have used several cannisters and Rainbow is about the bulkiest and most clumsy machine I have had. It does clean good, and it makes the house smell good, but not worth the back ache it gives me. I hope to find a buyer for it at some point, it is like new, only used lightly in my home.