Hmmm…
I really don’t know what you mean about BoF 3 
To be honest, I thought that it was pretty easy to level up (There were some pretty easy places to level throughout the whole game, I thought), and most of the fights were really easy, save for a few dungeons in the first half of the game, and some of the end bosses. The way the game is, anyways, is similar to Dragon Warrior in the way that ‘you’re at the right level if you can afford the best stuff’ sort of thing. I dunno, I just never was short on Zenny the entire game. In fact, when you pass by the Junk City for the first time, I bought that radical sword that you can buy for Ryu, that you’re not supposed to get til WAAAAAAY later in the game. I still had plenty money for everyone else’s equipment. That’s how much money I had
And I also thought the master system was good; you just make sure to use the masters around where you are, and you get a lot of nice stuff without having to travel much. It’s not like you really can’t just start training under someone again later Also, traveling in that game was pretty quick half the time, cos there’s not a lot of dungeons you have to walk your ass through just to get everywhere. Such a thing is even mitigated far more after you start using teleporters 
Lastly, I never had that ‘leave characters in the dust’ problem lke you had with say, Momo, for example, cos I leveled up everyone, except Peco, who is absolutely useless the entire game until he’s at absurdly high levels, and you never need his action for anything imparitive to the story; besides, it helps later in the game when there are those apprentices with ABSURD level up drawbacks like Ladon 
HP/MP - 6? Jesus godlord
Oh well though…BoF3 is one of my favorites in the series, so I guess we’ll just have our difference of opinion
Anyways, to answer your question…I’m really not sure if you’d like BoF4. In my opinion, it goes back to the somewhat mediocre feel of the SNES games. It’s better in a lot of ways, but I still think that every aspect in the game is lacking; it’s like a step down from BoF3 in a lot of ways.
Where to start, though? Let’s start from the ground up…
Graphics: This almost looks like a Sega version of BoF It’s a lot less colorful, and cartoon-like. The animation is a lot worse, and the game just feels a lot slower and boring because of it. It always kinda feels like it’s cloudy wherever you go…or it did for me
Music: Yoshino Aoki, one of the BoF3 composers, worked on this. He’s obviously not the one who decided to make BoF3 all jazz n’ funked out, which I REALLY liked. Most people don’t like it though, so maybe you’d like this music better. I was personally a fan of then juccuzi jazz/funk of BoF3, because it made really great ambience. I hate normal ambient music; I like to hear melody. This music is nice, cos it has a melody, AND it’s ‘just chillin’ music BoF4? That has a kind of psuedo orchestral feel to it. It’s not nearly as well pulled off as someone who normally does Orchestral music normally does, like, say, Sugiyama (Dragon Warrior), or Sakimoto (Ogre Battle games, Vagrant Story). So, overall, it wasn’t really BAD music, but it was mediocre, and a personal letdown for me.
Story: The story is kind of neat. There are a few twists and developments about it that I like. I personally feel, though, that the character interaction between all characters was not too well. I think BoF3 did a good job with character interaction, and the first half of the game was charming, with the “Little Kids Going On An Adventure” premise. This game really doesn’t have that. It’s not too bad, really, but it’s a step down from BoF3. What REALLY makes some of the story dumb is the FETCH quests. In BoF3 the fetch quests were relevant. For example: You need to get a boat, so you gotta fix the lighthouse, you gotta take care of the monster for the fairies (So they leave the lights on), and all that rot. Here’s a REAL BoF4 Sidequest: “I know where (the main villain) went, I saw him go by. But, if you wanna know, you have to go FETCH MY CHICKENS! THEY ESCAPED AND THEY’RE FAR MORE IMPORTANT THAN THE FATE OF THE WORLD! NOW SET FORTH!” Just…ugh. Reeeeeetarded.
Gameplay: Absolutely, the WORST part of this game For one, the masters system requires a stupid task out of just about ALL masters (All the ones I found anyways), and that’s something I really didn’t like about BoF3. They normally weren’t too annoying though. I can’t even remember the tasks I was supposed to do for BoF4, cos they just sounded so annoying that I didn’t care to do it. The fishing is really just not NEARLY as cool as BoF3. I don’t really know how to explain it, just…bleh. It’s aggrivating. The fighting has really gone down in fun…the Dragon System really isn’t as cool as the Gene System of BoF3. IfI remember correctly, it’s just ‘pick a dragon and voila’ like the older games. I honestly don’t remember though The dragons were all like, retardedly strong too, which made everything kinda easy. There’s a combo system in battle, which is kind of annoying. Basically, to do some of the stronger spells, you have to use different spells in succession (Like a strong ice spell and a strong some-other kinda spell makes Myollnir, I forgot the silly combinations, they were just dumb :P), and it’s really just more annoying than anything. I’d rather just learn the damn spells. You can use all six characters at once in a battle, which is pretty nice, but it really doesn’t add to the fun factor any, I think. And, the worst thing about the gameplay, is just how easy it is, but how infuriating it is at the same time. Example: The battle system in this game is random encounter…and I like to call it the ‘inconvenient random encounter system’. This isbecause, it seems you only get into fights RIGHT as you enter a place, RIGHT before you leave, RIGHT before you enter a room, open the chest, talk to the guy, hit the switch, fight the boss, etc. In any case, I got so fucking sick of this at one point in the game, that I just started running away from every fight. By the end of the game, the enemies could kill me pretty easily (Like 2-3 hits even), but, I was able to manage to get through the last dungeon and beat the game. I was at like, early level 30’s. I got on the net and read a faq, and found out that I was almost 15 levels behind the reccomended level for beating the game. That, is just, dumb. You shouldn’t be able to do that so easily in a game with such a linear combat system. Maybe I place too much of an emphasis on diffuculty in games, but I mean, SERIOUSLY. Can’t a game be just TOO damn easy that it’s stupid? Oh, and tag-on-the-extra-point, the world map is a dot-to-dot map and really slow to move around on. It’s annoying as all hell.
Now uh, you can go ahead and play it, if you WANT, but really. I just don’t understand the point. It’s not as bad as the SNES ones, but it’s just so much worse than BoF3. If you ask me, my verdict would be: Save your time, dish out a measly 20 bucks to play BoF: Dragon Quarter, which not only blows all the other BoF games clear to hell in EVERY aspect, but it’s also definitely the best PS2 RPG this year overall. Hell, it might be THE best RPG this year. And that’s all I have to say, about that.