Phantasy Star III wasn't horrid. It was simply different, and superior to PSII in many, many ways. It was and is and always will be marvellous. :p
PROS:
The story was sweet, the concept of multigenerations was nice. The town graphics were very detailed. The
concept of situation specific battle music was a cool idea(more on this in cons)
CONS:
The Battles graphics were nasty and reeked of NES graphics(especially considering PS1 had full landscapes...ps2 may have cheaped out on that one too but at least it didn't look as cheap).
The music was N-A-S-T-Y and looped every two seconds(the dungeon and shrine music was enough to drive you mad).
The battle music, while cool in concept, would mesh together to create utter chaos and, like all other music, sounded AWEFUL. They even stopped using the Sprite attack animations! And some of the monsters were very odd(moustache bearing statue in the buff waving it's finger at you for one). While I will admit DarkForce did look cool.
And, last but not least, who builds castles like those!?! The castles looked identical to Final Fantasy...1! From the NES DAYS.
Now PS3 got me into contemporary RPGs, so the nostalgia is great and all...but as a PS title, it deserved it's "black sheep" title.
And now we have PSO CARD..........*sob*
And thus endeth my editorial:)