I bought one of the Mouse-in-a-Box mice about 2 months ago for $9.99 (it had a price tag of $19.99, but a sign saying $39.99 - $20 instant rebate) ... I use it in Win2k, which Kensington does not support very well. Basically, it's a 3 button optical mouse for me since I can't get the side buttons working with MS or Logitech drivers, and Kensington drivers are pathetic. (note: works fine in 98)
As for its actual performance, I have noticed one problem in mine. Holding a mouse button down seems to send a repeating signal, rather than keeping one signal active. For example, in Quake 3 if I shoot the lightning gun, it's in pulses instead of a steady stream. Maybe I got a defective one? I don't know, but for $10 I'm happy with it as a general use mouse. Logitech Mouseman+ USB for everything else
