No. I mean, they have three guaranteed effort values of 3 upon catching them, but you can raise those yourself. Otherwise, they're just bigger and might have moves you can otherwise only get through tutoring. The Abra you caught can be made just as good with almost no additional effort. I suppose the one with a more optimal nature is better.
They're mostly a collectible.
Guinness Book of World Records is the name of the diary that belongs to
azuarc
, the winner of the Game of the Decade II guru contest.