The Scotch is the only serious (read: with real chances of an advantage) alternative to the Ruy, and has less theory.
The pure Vienna (with 3.f4) is not bad. White may equalize, but it's not so easy...
I don't really agree that the Scotch is the only serious alternative to the Ruy, what about the Scotch endgame? Is there anyway White can avoid it? I think the endgame is just equal.
The Scotch is the only serious (read: with real chances of an advantage) alternative to the Ruy, and has less theory.
The pure Vienna (with 3.f4) is not bad. White may equalize, but it's not so easy...