Turns out that turning off the EXP Share does, in fact, makes ORAS quite a bit more difficult. The new games are too easy, they said. Although Brawly, I'm sorry, but when my underleveled Ralts can torch you just by clicking Confusion four times, something's wrong.
This also makes you appreciate Amie bonuses a bit more, too. The 20% XP boost certainly helps, but there's nothing quite like your little guy shedding a status or dodging or just barely hanging on or nabbing a crit just when you need it. Amie bonuses without the EXP Share not only ease the pressure a bit, they also make the game a lot more exciting. It's not even just the bonuses themselves, either--it's the animation and text changes, too, which really help to build that emotional connection. Who knew hax could be so much fun?