Wings lacking the slot is probably the major drawback... Namin? is certain of it regardless of how she does not participate in PvP events. As for Mr. Kadar said, Flower Wing can boost a character up to MDef total of 50 and above without much difficult, but with team effort, how much can that accomplish? Storm Gust may do relatively little damage, but without marc the freeze remains which is still troubling as the other opponents will rush in to finish what the precasts cannot.
Lack of status armor card will also cause some problems in the long term defense either...
The only wings that can bypass the problem of lacking slots is Zodiac Wing and the ToH wings. Zodiac wing is horrible in terms of performance with the lowest defense among all wings. Only the ToH wings are really deemed usable with high defense, refinable to certain extent, and is slotted. However, ToH wings are so difficult to make and limited that they are no much of a concern in terms of balance.
*note: Namin? is speaking strictly of WoE situation where it is a team vs team context. Namin? recognize this identical argument and how people believe that wings ought to be weakened/banned/disabled during pvp events due to the unfairness for mage classes... let's leave that one aside for now.
