Just a few level exp. observations I've noticed in G/S:
1) Max. amount of level experience can be obtained by fighting a level 100 Blissey with a traded Pokemon holding onto a Lucky Egg, after which you'll get 12291 exp. points. Do not panic if you try this and see only 291 points...the window cuts off the first two digits.
2) Exp. Share does round down for level experience. I'm sure that this has been covered elsewhere.
Now to see what I'm classified as...
To claim mastery is to imply that there is nothing else to learn. Thus, I shall never be a Pokemon Master, since there's *always* something to learn.