Brilliant blend between MMO and single player experience. Not revolutionary but extremely fun and addictive.
A Realm Reborn is very true to its name. They have made the game enjoyable and an impressive work of art.
It starts of slow and a bit basic in its design. This is intentional to get players new into MMOs and PS3-players put up to speed with the quite advanced game mechanics (at certain points). As an MMO veteran this is a bit underwhelming but even so the first dungeons are fun.
Following the story and the quests/fates etc your first job to 50 will feel great. There are plenty of quests to go around and if you do a few fates here and there and some dungeons you will get there pretty fast. There are some levels which currently miss a few quests where it can be a bit grindy (Mostly compensated with lots of exp from FATEs currently).
Your second and third class up will be worse. Since quests are used up by the main one it will be grindy one way or the other. Sure you get an exp bonus when you reach 50 to get the others fast up but there will be grinding one way or the other.
The story requires a bit of detail just on its own. It is not the best story in a final fantasy game but it is up there in the top (surprisingly) and it is quite bold to put you with 7 other people in the last 3 story dungeons and when you do finish the story there will be a tear or two shed.
If the game is this good at launch (with a little help of reusing code from 1.0) it has a bright future with load of content (should you run out of the ones there are now).
This is a game highly recomended to MMO junkies, RPG fans or to people looking for a great game experience.