4 Okay but a little disappointing initially, but then...gigagav | 21/09/2011 | See all gigagav's reviews (1)The main thing wrong with this product is the price. It simply doesn't handle like a fifty quid mouse. It's reasonable to use, pretty smooth and so on but many Logitech products have a feel of quality about them that the M570 seems to lack. The scroll wheel, for example, could have been transplanted straight from a cheapo mouse (the damn thing literally scrapes as you roll it!). In summary , had I paid 15 notes less for this product I doubt I'd've batted an eyelid so the problem's definitely with the price. Heck, it's only a mouse, sorry trackball, and I'll get used to it (to get things in perspective). ........................................EDIT: Okay, I've had this thing for over a week now and it is actually fantastic to use. Great functionality and very comfortable!