I speak only from a PVE perspective, because i don't do PVP.
In my opinion, as a user of both, they are both very good considering healing logic, but the real difference is in the extra settings that only Leaves have and continue to add.
Like visual targeting (make you looks a lot less bottish, it actually targets your healing targets), hotkeys for nearly everything, blacklist and whitelist of targets, the possibility to change settings on the fly during the fight with a single key... all these things make me prefer Leaves over all the other resto routines.
On the other hand, truth to be told, apart from this specific moment in wich all the routines are in the process of updating, Leaves is often buggy, and everytime that's an update it brings new bugs with it, or at least it was the case in MoP. New wonderful functions > something that worked before doesn't work anymore.. it's really annoying at first, but Mirabis works always hard on resolving the new bugs, and considering the genius of Mirabis, after one year of using his routines, i can live with it.
What can i say? If you can't afford both Leaves and Oracle II, wich i recommend, in my opinion you should ask yourself this question:
All you want is topping the meters on LFR and normal pugs without too much hassle, configuration, and no problems? Go with Oracle.
You are a perfectionist and you want to top the meters playing with real pro's in Mythic difficulty? You know your class, want to use it 100% and be considered not only a good healer, but a good overall player? Go with Leaves.