Good but not good enough
Good
+It has that Final Fantasy feel which pretty much the point of getting the game.
+The community is fairly friendly
+The combo system provides a good mix of cooperation and coordination of party members.
+Character designs are great, my favorite (TaruTaru)
Bads
-Aggressise monsters will chase you forever until you zone out of the area.
-You can level down if you keep dying.
-Leveling becomes tedious and dull after reaching high levels
-Partying pretty much become a necessity after reaching level10 (if you want good exp)
-After reaching level50, you must do quests to reach higher levels and required to do so every 5 level thus forward.
-Quests can be a hassle to find at times due to there being no marker or indication of who has a quest available or not.
-Paying $100 for the HDD and game is not worth it, seeing the HDD is only used for FFXI and not really for anything else aside from PS2 saved games.
In short, FFXI is a good game. However, it targets the more hardcore fans and mmorpg players. It's not really solo-player friendly. Partying is about the only way to get anything done in the game. The price for the HDD and game can leave a sour taste in your mouth if you realized it's not the game for you.