Re:
I've had a Henry and a Dyson upright. I hated the Dyson, it was really noisy, the Henry isn't silent, but has a much mellower tone. The flex on the Dyson was really short, so that you'd have to unplug it and plug it into a closer socket all the time and the hose was also short and also really springy, so it was impossible to leave the vacuum at the bottom of the stairs and vacuum up them or to reach up to vacuum shelves etc.
The Henry on the other hand has the longest flex I've ever known on a vacuum cleaner, I can pretty much plug it in and do the whole house without having to move sockets if I pick one that's pretty central. The hose is also nice and long and it's fairly easy to hold motor part in one hand and vacuum with the other if it doesn't reach all the way up a flight of stairs, unlike the awkward Dyson.
The Henry is also a lot sturdier than the Dyson, it's made of a really tough plastic, whereas the Dyson was made of something quite brittle, one of the catches on it broke and I had to gaffer tape the thing together, I can't remember which now, it was a while ago.
If you do manage to lose or break any part of a Henry, you can buy a replacement part, even a whole new motor.