Not gonna lie, I was skeptical on buying this mouse because it wasn't a fan favorite. I was under the impression that my wrist will kill me or my forearm will be throbbing after a long 8 hours work day, but I would say that is negative for me. I do appreciate the options on the side as well as the illusiveness of the wheel though you are still in total control if you happen to over scroll and miss an important row ( heavy excel users will understand me on this one).
I've had it for about 3 weeks now and I'm content with it. I do understand that some may have issues with the functionality and maybe by how the mouse is designed but I 'd suggest that giving a go does help you get an idea of what kind off mouse would be ok using all day at work or just for personal/casual use.