You hold the B3 just like you would hold a pen or pencil, giving it a "natural feel" that helped Pure Overclock avoid "joint pain from the constant strain of twisting the wrist or awkward positioning." This ergonomic advantage isn't unique to the B3 -- previous generation Penclic mice follow the same design principles. But the newer version switches around some buttons to make it work for left-handed users. Technology Tell says this "significantly improves the comfort and handling" for right-handed individuals as well, and PC Mag appreciated the new layout for its "simpler user experience."
It may be easier and more comfy, but the B3 doesn't falter in use. Technology Tell says it "tracks accurately" and "performs well across all non-reflective surfaces." You can even set the dpi, though PC Mag only found the middle setting (1,200 dpi) ideal.
Whether you suffer from carpal tunnel or just enjoy the feel of holding a pen, the Penclic B3 is one mouse that will make your hands very, very happy.