But if you haven't noticed what SEBO are doing for years on end with Miele, its not as if they are competing with exact machines until probably the arrival of the E Airbelt family, which now offers a 3.5 litre capacity to similar capacity to the S6.
The C series for example had a bigger dust bag capacity to Miele's stable S500 and previous S700 models where the C series was pitched against. Whilst Miele uprated the power, SEBO stuck to their guns with the 1500 watt C2, C3 and associated added PN versions.
The K series has a 3 litre dust bag capacity, so it is both smaller on capacity than either the lovely S4 (a favourite model of mine) S6 and even previous models like the S300 series by Miele. Due to customer demand, power was increased from original 1800 watts to 2100 watts over a period of time.
Currently the D series by SEBO is bigger than the S8 on size, weight and slightly bigger dust bag capacity, almost twice as much cable and better built.
Whereas Miele may well trump SEBO for style, SEBO's newer cylinders in general are far better built in my experience. I've owned equal share of Miele products so I'm not that biased.
One of my daily drivers is my Miele S8. I dont know if I would go for a smaller Miele again - the way the bin lids open and bend far too easily isn't worth the money they cost to buy.