Yes, thanks. All of you are correct. Chris, thanks for reaching out to me with advice on buying a Sentria, I have not used one so may not get what I expect.
Thanks James, yes I guess I could sell the Sentria on as it is metal and is also very valuable.
Hi Stan! Yes I do have thick plush pile carpet in my room, yea. My Dyson DC25 struggles on it, because it leaves the carpet spotless on the surface, but when I put the vacuum on a random part of the carpet and apply pressure to the motor head, there's larger debris living in the carpet that comes out. I had to get the stair tool on the wand and scrub very hard, or use the crevice tool. It is a pain.
I wanted a Kirby because of its power. Of course a dirty air has a lot more suction at the cleaner head than a clean air one, so thought it may be a good piece of kit for my thick carpet which is like American style, approx 2 cm, or just about an inch thick.
In our house we have that thick carpets, burber carpet, large area rugs which are plush, but we will get new carpets. On the stairs and landing we will get plush instead of the burber.
Kind regards 
Tayyab
