I finished Persona 4 Golden last night. Hard mode, best ending. Just under 58 hours. And well, when I finished, I was tempted to start right back again on New Game+. That never happens.
Persona 3 was a great RPG and Persona 4 fixed many of its problems, while improving on its strengths to become one of my favorite games of all time. Likewise, Persona 4 Golden fixes & improves on the original P4 release. It's a much more user-friendly game this time around - you can skip & rewind story sequences, creating new personas is much less of a hassle (you can pick inherited abilities & you can also see a list of all personas that you can currently create), death is less of a penalty (it starts you back at the beginning of that floor instead of at your last save), and you can easily see what you can do each day via the online feature. And since it's a game that still has save spots, it's wonderful to have it on a portable device so that you can just stop and start wherever you like.
Some people have complained that there is ONLY one new dungeon in the Golden version and ONLY 2 new S-Links compared to Persona 3: FES which added a whole slew of new dungeons & Persona 3 Portable which added an entire new playable protagonist and a bunch of new S-Links for them. I think these people are missing the point. Yes, there's only one new dungeon but it's an interesting one with some new gameplay ideas and some neat story to it and it adds another 3 hours or so to the game. Yes, there are only 2 new S-Links, but between the new S-Links & the new dungeon, the overall story feels a lot more coherent (especially the ending which was one of the weak points of the original version). And though those are the big additions, they added tons of little stuff here and there in the form of various events & activities you can participate in. For example, you can now hang out with party members in the evening and you'll get fun little conversations depending on who you're hanging out with and how far along in the story you are. I was also surprised to find that there's a new extended epilogue ending to the game if you get the best ending & complete the bonus dungeon. There's also a large Special Feature section of the game that lets you do things like watch cutscenes & trailers, listen to music, watch & listen to songs from the Persona 3 & 4 concerts, view concept art, and even learn about the psychology behind Persona's world.
As far as gameplay changes go, there are two that I think improve the Persona 4 experience greatly. First, they did away with the twitch-based "Select a Card while it's quickly rotating in front of you" game from the previous Persona versions and have replace it with a very fun mini-puzzle game. A number of cards are placed in front of you, each with a positive or negative effect. Some cards (mostly the negative ones) also allow you to pick additional cards and if you manage to select every card, you get an additional bonus so it becomes a fun little game to try to maximize your bonuses after each battle.
The other big change to gameplay they made is with your allies. They've rebalanced their skillsets and also allowed them to gain additional abilities via S-Link ranks & taking day trips with them. You can also give them XP & stat bonuses by going to see movies with them (but just once per character per movie). The end result is that your allies feel much closer to the main character's power level than they did in Persona 3 & 4 (at least, until you fuse the perfect persona for your main character that's immune to pretty much everything).
If I had to complain about one thing, though, it would be the difficulty cure. Persona 4 Golden has an inverse difficulty curve - the first couple of bosses are the hardest in the game since you're still limited in your party options, everyone's S-Link levels are low and you still have weak persona. However, if you play your cards right, you just keep getting more and more powerful with the result that I'm guessing most people will start to feel overpowered before the game is over, at which point, you're just going through the motions trying to finish things off with no real challenge from anything other than maybe the occasional boss.
Persona 4 Golden is easily Atlus' best remake to date of what is probably their best game to date. If you own a Vita & like RPGs, it's a must-have and if you don't have a Vita yet, it's a strong reason to get one.