I do like what they did with JLU which made flash seem more like he was always trying to get to grips with his power levels and not push himself that far. He really came into his own when luthor stole his body and what not.
it's a shame with so many central characters, flash and the martian generally took a back seat to everything else but i guess they used his young and comic nature to play as the heart of the team and his influence is seen in the justice lords when he isn't there.
Alas, if I was going to do that braniac punch, I would have first had supes throw him in one direction and run in the other...they'd both meet half way across the world near the sahara desert and supes would give him a nuke emitting dragon punch sending him into the stratosphere (causing all the sand to turn into glass). the site of darksied flying through the atmosphere makes everyone stop in awe. darkseid is punched and hits the moon, causing a massive crater in it. He then struggles to get back up to his feet and jumps back into orbit (poosibly landing on supes) to carry on with the fight.