I have limited mobility so I wanted something fairly light. Although the vacuum is extremely efficient, it is top-heavy and I found it quite difficult to manoeuvre until I got use to it, but having said that, it's worth persevering as it is far more efficient than my old Panasonic vacuum was (now retired to the garden summerhouse/shed). I had just used that immediately before I cleaned the carpet with the Shark, and was astounded at the amount of fluff/dirt/cat hairs it collected. A very good feature for me is the machine's ability to get under furniture without me bending too low. If I were perfectly able, this wouldn't matter too much, but for me it makes a good machine perfect. It's very easy to operate and I'm glad to have bought it. We also have a Dyson cylinder machine, and although it is good, it's not as good as the Shark.
