FES is a welcomed addition and a must for those who have played Persona 3, the 40+ hours of extra gameplay and a conclusion to the intriguing story are well worth the price-tag (especially since the price has dropped since it came out) For those who haven't even played Persona 3, GET THIS VERSION because it has both the original Persona 3 and the added chapter with a whole bunch of nifty features(such as turning Personas into weapons).
Unfortunately I did have a major complaint. The "Persona Compendium" isn't in the new story. For the those unfamiliar with the game, the compendium allowed you to buy the personas you once had for a fee. This could mean that I could combine two personas to make a really cool new kind, and then buy back the two original ones I had. In FES, if you want to get your hands the best Personas, you will need to know what you need to make them and where to get them. (The compendium is still in the original part of the game though).
To those who would look at this and say its just a shameless cash-grab that is nothing more than a carbon copy of a game, then I will say they are only half-right. Yes it has the many of the same things from the original but will deliver if you enjoyed the story of Persona 3(Especially the ending...WOW)
Verdict: If you love the Persona games then you *should* already have this, if you normally are not a fan of grinding and anime style characters and Japanese rap(it plays a lot in the background) then don't buy it.
If you are into goods stories in games then at least give this thing a rent.
Or...you could play it for the giant penis monster...