Reactives are weaker and generate a lot more hate. I really used them a lot, and they are indeed not going to be the mainstay now.
I've been having a huge problem with implied targeting not working correctly, especially with smites and debuffs. With the shift away from reactive heals to direct heals... It's not really feasible to be shifting targets during a fight to debuff or smite.
I'm still getting all jammed up with the shared timer changes too, and the changes to what will and won't stack.
It's going to take a while.
It is also more painful to try to cast when you do have aggro now... more interrupts it seems.
On the flip side, I seem to be finishing solo fights with a lot more mana left in the tank now.