Best professional glass cutters?

I am looking for glass cutters (scorers) for use on thick or stained glass.

Some recommend carbide wheels like some models (which?) of Fletcher.

Some recommend Toyo, such as this one: http://www.amazon.com/Toyo-Wheel-Thick-Glass-Cutter/dp/B001C7XE8A/ref=pd_sim_sbs_hi_13

Does anyone have experience in cutting 1/2 inch glass using hand tools?