I have a Sebo, sparkle = bought it almost a year ago, and I'm very pleased with it! Had a Dyson for many years, but now I'm getting a bit old and creaky, found it a bit heavy to lug around, especially getting it upstairs.
As I prefer an upright to a cylinder, I wouldn't consider a Henry or Miele (tho I know Miele now do uprights), and I checked various Sebo models out at John Lewis for manoeuvrability.
Sebos aren't lightweight, but they are almost powerdriven, so glide along very easily, and with a low profile head, will go under furniture that the Dysons can't manage. I also like the fact they have bags (got fed up with emptying Dyson's canister and getting dust everywhere!), and the bags last absolutely ages - they'll take 5 litres of dust.
My Dyson now lives upstairs, and the Sebo downstairs, so no more lugging!
Sebo rate very well in the Which? trials, and have been used in hospitals and commercial premises for a long time, which is good enough for me!
This is the one I got.