I have recently bought a GTECH Air Ram K9 and I love it! It is powerful, quite light and easily manoeuvreable even on the stairs. However, it doesn't quite reach right up to the skirting boards and has no attachments. I also have a hand held Dyson, for which I bought an extension tube and head to make it like the new ones, but it has far less suction, probably because the motor is so far from the head. I have cat litter tread on my carpets and the GTECH is so easy just to whizz over, whereas the Dyson can't cope with the weight of the bits and deposits some of them back onto the floor. The Dyson holds a charge for only 10-15 minutes, but the GTECH lasts for weeks. You remove the battery to charge it. so you don't need to store the whole machine near a plug point. You can also buy a spare battery if you want, but I haven't found the need. There are 4 lights on the vacuum when fully charged so when it runs down to one light, I know it will need a charge before the next use.
I like the GTECH cleaner so much that I have also bought their grass strimmer and hedge cutter. I was looking at their bike too, but at £1000 I can't justify it for only occasional use.
Good luck with whichever you choose.