My feeling is that the Scion tC design is successful because it lacks a moat and drain channels in the A-pillars. It drains in an entirely different way.
The important point to Marnet is to look at the design of the sunroof. If it has a moat, of it has an enclosed drain channel, it stands a fair chance of eventually leaking. Drains clog up and neoprene eventually deteriorates, albeit very, very slowly. Neoprene is also subject to erosion failure. A good design provides no leak path even if the neoprene deteriorates.