First of all, I love it. I think people are saying they hate it is because it changed from what they are used to.
I think we need to put Mana Bars back on the teammate icons,
we need to put the Champion Information (Default hotkey "C") Bigger or in the middle like a POP-UP
also other minor things like put the GAME TIME back on UPPER RIGHT. but thats a matter of getting used to it.
also the LEVEL UP ARROWS Need to be NOT BE THERE when the skill is MAXED. it currently shows up as a GREYSCALED Arrow instead of being completely not there.
these are just my opinions though. Ive been playing since 2012 so this is from a perspective of someone used to the old HUD.