For years I thought Miele were the master of their canister design and I still think that there is a lot of good in the machines, but the problem with Miele is that whilst the main body machines are light, everything else seems to be less thought out IMHO.
The standard twin telescopic height adjustable tubes on their own weigh close to 600g. Sebo's stainless steel tubing on the D series weighs 504grams and the cheaper ones supplied on the K series that have an outer sheathed plastic coating at the top with the metal telescopic at the bottom weighs 484grams - or close enough to 500g. The copied sebo handle on the Miele S5 handle weighs 280g on its own compared to Sebo's 200g handle. The Miele S5 has a 1.8 metre hose - the D series has 2.1 metres right across the board including the electrified hose on the D4 Premium.
Compared to the smaller K series when I owned my S371, S4210 and latest S6 series, the latter two machines are a lot lighter to carry but they all have the same hose measurement and twin suction pipes. Now, one could argue that the Miele suction pipes do give you an increased height, but the hose isn't long enough when compared to the bigger length that Sebo supply. I've noticed that I don't put my back out as much when I'm dragging a Sebo canister along the floor - certainly only when using suction only floor heads or at best, air driven turbo brushes together with the longer hose compensates on the tubing provided with the K series. Ultimately then the only work out you're doing at the time is stretching out the hose and being in control of the handle, pipes and floor head in front of you.
Equally though there are downsides - if you're desperate for the PN model, you do have to consider that the powerhead from the Felix is the same one, taken originally from the K series, so it is a lot heavier than Miele's PN heads will ever be - plus the electrified pipes on the D4 are also slightly heavier since they are taken from the K series to minimise extra costs. I'm not a fan of the D4 in general because of the heavier weight - it is a good compromise with all things considered - but the weight savings are best with the non-electrified versions as opposed to the D4 Premium.
The Felix upright on the other hand is a good machine but it is isn't very good when used as a hand held machine. I know Sebo were thinking "Vorwerk" when they produced that part of the design as an option, but I find the whole idea too bulky and much prefer to have the Felix using the PN supplied, or alternatively as a suction only model with the deluxe "Kombi" floor head fitted - thus changing it into a versatile hard floor cleaner - compared to using standard suction only floor heads, the Kombi allows the Felix to lay flat completely - none of this "park stub at the back" dragging along the floor like a standard, normal canister, or having to swing the handle at an angle to get the floor head to lay flat.
This is what I like about Sebo. They look at the design aspects first and the engineering in tandem. Sometimes it doesn't always work out - whilst I think the D is a fantastic rival to the Miele S5, the tools at the back of the machine are less thought out - when it comes to cleaning stairs, you have to think before hand what you'll need in terms of the smaller cleaning tool and get it before the machine is stored in the upright position for compact cleaning - Miele's trump card here is the better flap at the front.
It is true that whilst Sebo models lack a certain "chrome and bling," aspect compared to Miele, their thoughtfulness in other areas is more spot on for the customer rather than building to a mass design and then, kitting it out with less than thoughtful features - but it only takes the eagle eye of a consumer who has been ripped off or feels let down by the price they've paid : )