I've used both of them and think they're both good choices. Although going to a store and feeling the different mouses is a start, I think you really need to use them to figure out what mouse is best for you. I ran into this problem because when I went into the store, the dual optical felt the best to me. Then when I started using it, I found out that I don't actually hold my hand over the mouse like normal. I just use my fingers to grip the sides and don't even touch the mouse with my palm. I found that ambidextrous mice fit my mousing style the best. I think my favorite mouse of all time is my Microsoft Wheel Mouse Optical. My second favorite mouse is the plain jane logitech optical (the blue or red ones). It is proven that microsoft mice sport the best optical sensor, but it is really hard to tell the difference between them. You also may want to know that the dual optical doesn't have 1600DPI. The two sensors don't double the DPI, they just make it track better on bad surfaces. The mouse actually decides which sensor has the best reading each time it reads the position. It doesn't combine the readings into one. Some have said how they didn't like the microsoft botton action. It isn't really that the buttons are soft, they just don't travel as long to click. The button action is really a personal opinion, but I feel I can fire a tiny bit fast with the microsoft mice. It is worth mentioning that on my main system I use the plain jane logitech (the main reason is because the beige of the microsoft mouse that I like doesn't match my black PC, in this case function follows form).