bill - 1:23 am on Apr 12, 2012 (gmt 0)
One of the things that threw me was that in Japan they can't use the name Logitech. They use Logicool instead. the packaging looks the same. When I was shopping I kept looking for the Logitech models that I had read reviews on. I thought all the Logicool models were Chinese ripoffs of Logitech. A few web searches finally put me straight.
The Performance M950 was not cheap, but it's the most frequently used piece of hardware after my keyboard and I didn't want to skimp.
That said, I didn't see the Logitech Trackman Marble in the stores...just the Wireless Trackball M570 which is the thumb-ball unit.