Originally posted by: bex0rs
I would vote for the Logitech Dual optical.
I have it and the Intellimouse Explorer 3.0 and each has its advantages. The ie3 does track better in general, but if you are using a mousepad and tend not to really twitch then both mice track equally well. I find that the logitech works fine for everything unless I try to move it across my mousepad as fast as my arm well move - then yes, it will skip. My only real complaint with how the ie3 moves is that it seems to stick to my mousepad if I haven't moved it for more than about half a second. This is actually really annoying and for me makes it unsuitable for gaming. However, once it is in motion it moves quiet easily. The logitech does not have this initial movement problem, presumably due to smaller mouse "feet" or perhaps a different material for the feet.
In terms of feel in my hand, the ms mouse feels more natural at first so many people would probably pick it in a store, but the logitech really does feel better in the long run and IMO it is easier to aim with it. I also find the ie3 to be too light for gaming (but just about right for general desktop navigation). And finally, the side button on the logitech is more comfortable to push than either side button on the ie3, plus the two main buttons on the ie3 seem to be way too easy to push.
If you are really serious, be sure to get a good mousepad as well. I would recommend getting a fUnc pad and using the textured side.
~bex0rs
Ditto.