Just for some more information - Persona games are easier spinoffs of the original SMT games that add stuff like relationships and a day/night cycle and calendar system. SMT games are generally much more difficult and stick to the core gameplay systems. Persona 4 Golden is a pretty damn good game though.
SMT 4 has added a lot of things to make it easier than usual SMT games if you wish. Along with general improvements to Demon Fusion and being able to pass on skills when you fuse them (This is usually a Persona only thing), in addition to being able to take skills for your Main Character from your demons when they learn their final skills.
I'm about level 30 and just finished Ikebukuro - going 3 MAG/1 AGI/1 LUK with my MC and loading him up with elemental spells.
Game is definitely worth it, especially if you have Fire Emblem Awakenings. Then you can register both and get a code for $30 E-Shop credit that you can apply to the Wii U or 3DS (they don't share credit balances, so choose wisely - may change with an upcoming update that adds Nintendo Network ID system to 3DS).
Only if you get a first run printed version, the 2nd wave won't have that stuff.Do not purchase the game on the E-Shop. While convenient, you are paying the same price for the game should you order the boxed version, but losing out on all the goodies. For the same price, you get the cartridge, the CD sound track, and a very good mini strategy guide.