I would like to make a simple suggestion that could make potions more useful. Personally, the current effects of most potions seem to be reasonable to me except for the buff potions like vitality. However, the issue with all potions is the Recast. The fact that every single potion goes on cool-down despite them being different types makes potions useless.
For example, let's say I have the following potions in my inventory.
X-Potion 2m Recast
X-Ether 5m Recast
X-Potion Strength 5m Recast
Antidote 1m Recast
Eye drops 1m Recast
I decide to use an X-Ether which has a 5 minute Recast time, however once I use it every single potion in my inventory can't be used for 5 minutes. This makes the other cool-downs of the potions pointless and makes using potions in general worthless.