I dont see anything bad about potions but let me support you : Pots suck,i want see them go...bla bla ble blu...
I hope i helped.
The potions in Grand Fantasia dont heal for very much and have long cooldowns on the IMO Most monster there hit what the potions heal you for if you are not a warrior :S
The best potion system has Atlantica online. You can use them in combat but are not really needed since monsters are not so agressive and the battles end really fast if you what you are doing and what your targets are. so after every battle you can sit and heal yourself with potions or by resting :P