Personally I think wireless keyboards/mice are utter crap, then agian I only used utter crap ones (could be all). The batteries die continuously/have to recharge em, lag lag lag lag and if you use a logitech in general, you won't have very good driver support. For example I had to work on a computer at my cousin's house and they had some logitech mice (wireless and non) and the computers were outta wack so when I came to work on them, the mice either wouldn't move at all or jittered a lot, forcing me to install everything simply from the keyboard (has done this many times but is irritating). Microsoft Explorer mice are great (my belief) because even if you don't install thier mice drivers from the CD, there is still excellent support in windows and are very repsonsive (can't vouch for wireless though). The support is so good, I can even use these mice in Windows 3.1 with out a hitch!(Obviously no USB) One more note, most ppl I have encountered don't know this but using the USB should be a last resort when using mice/keyboards since USB has a tendancy to lag apposed to PS/2 which has never lagged on in me in games/ in general.