I know several C6 owners (with solid & clear targa tops). None have bitched about leaking. The earlier years (think Jim's is a '08?) had the squeaking issue which mostly resolves with lubrication along the seals. I don't think the polycarbonate is super sensitive to scratching but then again, it's an exterior car panel. SCM is probably dead on with less chassis flex = less/no leaking. And this will be GM's 3rd go round with this targa setup since the C5 (I'm discounting the C4 since it wasn't latched). Even they should be able to get it perfect this time!