The new EXP system is one of the few criticisms I have towards the game. I already despise level grinding(Pokemon isn't as bad as some RPGs are about it, but I still hate that most of my hours are put into training instead of the actual story). The fact that good bit of the Unova pokemon evolve at high levels makes this even more frustrating. I know about Audino and that I'll eventually get the Exp. Share, but still.
I don't know if I still need to get more used it or not, but I prefer the old system.