Replacement for Logitech VX revolution

[lovelyhead]

I have had a Logitech VX revolution mouse for the last few years and it is the most comfortable mouse I have ever used. It is now starting to fail a bit so I am looking for a replacement. It seems that Logitech's marathon mouse is the spiritual successor to the VX but it has issues with an offset laser.

Has anyone replaced their VX and if so what with? I should add that any replacement needs to be wireless due to my setup. I don't really have a maximum budget.

Thanks in advance!