Well, against seismitoad you can't play max potion since you are item locked, depending on your build you could run AZ to help a little bit with that. Against any deck that doesn't OHKO you... You will 1HKO them, meaning, you will kill 2 Landorus, 2 Manectrics or 2 Kyogres before they kill one...
My opinion right now is, Aromatisse doesn't add much value to most decks in the format. I've been a fairy player since I re-started playing last year and Aromatisse was helpful for a long time.
Moving your energy back, playing max potion and leaving your opponent with a 230 HP completely healed...
I've just tried the deck myself. It can get clunky quite often so I made a few changes:
I cut down 1 colress in favor of a Shauna, or it could be the 4th N. I don't know if it's my luck, but I keep drawing colress in the begining when I really need to set up and neither player has too many...