hmm I'd stick with a Dyson too. Ours is maybe 5 years old now? And still has efficient suction and leaves the carpet lovely afterwards.
We have a Henry too, and although very cute to have a little face following you around as you hoover, i find unless i am specifically careful where he wheels himself, he bashes into my furniture!
uhh Miele are well reputed also, but i have a certain element of "stick to what you know". If you're dyson did what it said on the tin, and was reliable then get another one.