I have a sebo Dart which is sold as the commercial version of the felix, and just as Colin said, I have had customers think that I have finished the job before the serious cleaning ahs even started. The Dart is slightly more manoverable than the BS machines with a 30cm brush, so it would cover less ground than the BS36/46 options.
Sebo said that the Felix, (domestic) and the Dar,t (commercial), are exactly the same machine, but the domestic one comes with a 3 or 5 year warranty, but the Dart with 1 year only, because of ots expected heavier usage.
I am very pleased with the machine, but still use Henrys for a lot of general vacuuming.
Cheers
Mike