[Maarten]

Marantz made some machines for Philips in the late 1980's and early 1990's, so you might have encountered one without realising. They can be recognised by the Panasonic mechanism and the 'not quite Philips or Panasonic' electronics. In the turbo deck days they did make one or two multisystem turbo mechanism recorders as well, which were sold both as Philips and as Grundig in different European countries.

I don't remember Sharp machines as being particularly slow. I always thought of the Panasonic G mechanism as being particularly slow, though.