I'm using this mouse and it's awesome imo. Switched from ms 3.0 and its slightly smaller, but slightly bigger than 1.1 with a nice shape.

Sensor is the best I've used and the weight doesn't bother me although comparing it to others yes it is heavy. Only thing I felt is that the mousefeet wore out quite quick, although they are fine still after a few months. But I've been using hyperglides for years so I guess I'm just used to better quality.

Don't think you can change the weight, at least there is no way to remove anything without doing it yourself.