Nilfisk advance dominated the industrial market but the older Danish made stuff got too expensive so they bought CFM Italy for the big stuff and Alto-Wap for the smaller stuff
They sell a bewildering array of stuff from plastic tat to 3 phase monsters. The IVB , Attix and Aero are good - a lot of power tool brands private label them
Festool - own several older Alto-Wap SR machines very good , used some CTs, seem good also
Numatic - used lots and hate them
I haven't used Starmix (mafell,metabo) Karcher (bosch) IPC-soteco (trend,dynabrade,nederman) so won't comment on them
Matt