Glass coating for shower doors

Has anyone any experience with the vapor deposition coating on glass offered by some glaziers? Different brand names from different suppliers, but basically, after the glass is cut, drilled, and tempered, they put it in a big vacuum chamber and fuse a coating onto the glass (sort of like multicoating a lense). The coating microscopically fills the rough surface (yeah, I know you thought glass was smooth, but it isn't!) so that water beads up and runs off; sort of like using RainX on your windshield, except it is permanent. At one place, it added about $7/sqft. Wondering if anyone has it and if they like it.