The turbo brush on the K3 is an older wessel werk head that Dyson used as far back as the DC05 and early DC08's. Its a good floorhead, but like you say, you have to dismantle it with a screwdriver to clean it, as I found out with a Dyson version. It does move across carpet well though.
The mini turbo brush on the Sebo range is also an old version of the Miele mini turbo brush, but uses a 37.5mm fitting so only Sebo heads will fit.
