Not at all Simon! I remember you told me you have one awhile back too!
I love the M570. I have used the Logitech thumb trackballs since like 2001. But they lost that lawsuit and that once great mouse is now the M570 which is okay, but I still liked the old version, it was way more durable. They still sell the old ones but they are over $200 because of limited supplies. I recently bought the Proteus Spectrum but I just cannot master using a regular mouse, well, I could but it is too frustrating to deal with. I actually have a backup M570 coming in the mail tomorrow!
I try to convert people every time I see a "What mouse" thread
ETA: Check this out Simon
[ame="http://www.amazon.com/ELECOM-Wireless-button-function-M-XT3DRBK/dp/B016QCPNUW?ie=UTF8&keywords=elecom%20thumb%20trackball&qid=1463170771&ref_=sr_1_3&refinements=p_85%3A2470955011&rps=1&sr=8-3"]Amazon.com: ELECOM Wireless track ball mouse 6 button Tilt function Black M-XT3DRBK: Computers & Accessories@@AMEPARAM@@http://ecx.images-amazon.com/images/I/416TG61%2Bi7L.@@AMEPARAM@@416TG61%2Bi7L[/ame]
This was the mouse we tried out before the logitech thumb trackballs and it was horrid. It was a different brand but looked just like this.
[ame="http://www.amazon.com/YUMQUA-Y-01-Portable-Finger-Trackball/dp/B00X3LEJBE?ie=UTF8&keywords=elecom%20thumb%20trackball&psc=1&qid=1463170812&ref_=sr_1_6&sr=8-6-spons"]Amazon.com: YUMQUA Y-01 Portable Finger Hand Held 4D Usb Mini Trackball Mouse / Fits Left and Right Handed Users Great for Laptop Lovers: Computers & Accessories@@AMEPARAM@@http://ecx.images-amazon.com/images/I/51tMQvaW7RL.@@AMEPARAM@@51tMQvaW7RL[/ame]