Need a new mouse. (I think dropped my G7 in the garbage bin and threw it away..

)
I was thinking of getting the MX revolution and then I realized logitech just came out with a new mouse (to replace the mx revolution i think).
Shape and buttons looks almost identical, except it features a "darkfield" technology that lets you use the mouse on glass surface.
Anyone tried the new mouse so far? Does it really work "well" on glass?
I have a glass table and it would be a nice thing to be able to use it on the glass top. (I usually use it with a mousepad under the keyboard tray)
Cheapest MX revolution I found locally is $69, where else the performance MX is $120.
Is it worth the price difference? or I am better off sticking with the MX revolution?