[EvilGenius]

What advatange do the high ribbed clay guns provide?

[TurtlePhish]

Sight plane, heat mirage elimination, looks cool to some people. Slope can effect point of impact.

[EvilGenius]

Why the elevated sight plane?

[oneounceload]

Nice to keep head more erect for trap-style rising targets where you "float" the bird above the bead. Some in sporting clays are using them as well; however it makes, IMO, dropping targets that much harder - and in sporting clays you get a lot of dropping targets

[EvilGenius]

Ah ok.

I've been watchin trap and skeet finals on the ISSF channel on youtube all day and couldn't figure it out.

[Red Cent]

To add to oneounceload, the "floating" of the bird allows you to keep the bird in sight/view. With a field gun, it is neccessary to "blot out" the bird and shoot as you follow through. Some handle handle this very well. Long ago, I used to shoot trap with an 1148 semi. Tough going. The high rib builds in your lead/rise.

[Virginian]

Also, being able to keep the bore line lower compared to a more conventional set up reduced barrel rise after the first shot. And I have also heard some say it helps in the area of felt recoil.
99.9% of things are in your head, and if you think it works it probably will.