I have a Sebo D4, which I like well enough so far. I think it is very solidly made, and somehow sub $1k (barely) seemed reasonably priced vs Miele. However, I do wish they had a combi nozzle vs the rather bad hard floor tool it came with (it doesn't turn enough ways, so is very uncomfortable to get under things - the ET-1 powerhead almost has the other problem, turns too many ways!)... Though mainly the ET-1 is sufficient, except for the desire I have to not track in whatever gets stuck to the bottom from the hard floors to the carpets. If you don't have that (maybe stupid) worry, you don't need other cleaner heads IMO.
It's a little heavier than I'd like, but the bag size, power (in the US anyway), and performance is very nice. I love the idea of the easy clean and change brushroll - I think that may have been the deciding point for me vs Miele.
I do kind of wish it was as easy to bang around as the Oreck Iron Man (weights almost nothing, and surprisingly resilient for how cheaply it's made / seems made), and the 360 rotation at the handle end helps you not get the hose all tangled up / trying to kink. There's really no replacement for that IMO. But I also think the power head is worth it, and there's not a great reliable way to have a 360 degree electrical connection.
For storage, it would be nice if the bag had a little sealing flap that auto "closed" like the Oreck so you could just disconnect the hose - I feel like that would let the Sebo take up less room.
However, the Sebo is better than the Iron Man on carpets, it saves me from switching vacuums when going from hard floor to carpet (save all work if you only use the powerhead - just press the button on the powerhead - again, it would be nice if this was handle controlled), it's like 50% or less as loud as the Iron Man, and isn't a high pitched whine that hurts your ears after a bit, and the bag doesn't fill up every 3rd time you use it. The filtration is hands down 10x better than the Iron Man, but that's not a huge concern for me - again why I didn't rate that difference higher for the Miele. The Airbelt system works well enough, though even banging around the Iron Man didn't really bother me as I have mostly "soft / plush" furniture, so it wasn't going to mar it. I'm also young enough that the 16lbs or whatever, while noticeable, isn't a problem as much as the potential awkwardness.
It works quite well, but has some noticeable downsides too. I'll probably compare it better soon, but I have to finish off my Iron Man bags (one more to go)...