I honestly dislike the changes from 6/17, it moves to much power from her base kit onto the ult.
Leona is the only full all-in support, she has no fall back options, no way out, she either goes in all the way or she does nothing. As such, it is important that her all in is very threatening even early on, else she will get bullied pre 6 as ranged champs could poke her without really fearing her retaliation.
I'm also a big fan of sololane leona and while the cd buff for Q is nice, the overall damage loss will hurt her tradeing and waveclear quite a bit, makeing her rather snowbally as she will rely ona now really strong all in whenever her ult is up.
Jungle Leona will also suffer alot from those changes in her already not that great clearspeed.