Equip sets are a great feature most of the time, however they have a pretty fundamental failing. They don't have a priority system.

Lets say I'm on WHM and I have a macro using equipsets, the first line equips my potency set, then the 2nd line casts the spell then after a /wait 2 it equips my refresh gear.

If I press the macro, and then press it again too quickly if will very often not equip my potency gear gear at all, they interrupted each other.

The equipset system needs a priority system, or a specific set idle set that automatically equips after using a equip set.

The only way to guarantee an equip set works every time, is to have a specific macro to put your idle set on manually after every cast. Which is really tiring.