Nice price on a fine mouse! I've had this one for about 10 months (got it for $35 shipped even back then! 🙂)
Setpoint is pretty crappy and it uses way too much memory for what it does, regardless of how cheap memory is now. Just look at what it does compared to the download size and it's a big 😕 But I put up with it for app profiles and customizable DPI adjustments, though I prefer the 3.x versions.
IMO, the DPI on the fly is one of the best parts, much better than the weight customization. As said above, there is three default DPI settings but with Setpoint running you have five and they are customizable. Yes every game has sensitivity adjustments, even specific ones for vehicles, etc like in BF2, but I do find myself using the DPI switching often, especially say to play sniper or whatever. I generally have my five DPI adjustments fairly close, maybe like 300-1200 separated by a couple hundred.
People who like a lot of mouse buttons might find it limited when you do actually use the DPI on the fly buttons, only one side button, and the tilt wheel can't be bound in games. It is just four buttons + wheel then. You can have six if you give up DPI switching, but really why they didn't add a second side button on such an expensive/high end mouse is beyond me. Also I have hoped that I could use just one of the two DPI buttons for DPI switching (say just up, when you reach the highest, next press goes to the lowest). But that is pretty minor, as I'm not someone who needs a lot of mouse buttons.
Also, the middle button is a bit tricky to press down without touching something else. You get used to it after a while but even after all this time I still occasionally hit tilt-right on accident when middle-clicking links.
Just my thoughts for anyone considering this. You'll probably find some similar comments in reviews on the web. It is very very nice for this price.