I bought a Gtech Air Ram a few months ago, and love it. It is lightweight and really quite powerful. On one full charge, it is more than enough to do up and downstairs. We have carpets everywhere, except for the kitchen, loos, hall and porches back and front. The changes in level do not matter, and it is easy to empty, which do need doing fairly frequently. The red charging light appears if the dust container is full and the filters dusty. Once cleaned, off it goes again without recharging. The only fiddly bit is when you take out and wash the filters. I've now got the hang of it, but it took awhile to learn the knack. It doesn't have a flexible hose for corners etc, but use either "Henry" or my little Miele for that when I feel virtuous 