Last week i bought new mouse (actually my girl friend bought me it for X'mas cos i told i want it) - "Microsoft Explorer Mouse" with "BlueTrack" technology.

And what i can say about it?
It's TOTAL CRAP and it's TOTAL BULLSHIT about "Say Goodbye to Laser". It works as worse as any 5$ mouse. If you put it on not flat surface cursors shivers or moves up on desktop, even if you put it on white page of paper (i did it on A4) you can observe same movement up (not always). Come on! It's 100$ mouse. I'm so disappointed that i spend so much money on this crap mouse that i would really appreciate if Microsoft would give back my money or they would give me mouse what works good.
And believe me - i know how mouse should work.
Previously i had Logitech G7

And it really works good on any surface i was using it on. The only downside was you have to change batteries every evening, but with fast-swap it wasn't a big problem.