As someone who loved Generations of War (or Record of Agarest War as it was called on Xbox 360 NA), I played the Record of Agarest War first, then played Record of Agarest War Zero after, and thought it was fine. I loved the combat, and didn't really feel the "grindy" nature of it too much (this is coming from someone who doesn't mind grinding a little in game anyway). I even played through the original game twice, once for fun and the second to clean up the achievements by following a true path guide.
For tips and tricks, I recommend checking out the Playstation Trophies guide, and specifically reading the Roadmap section. Record of Agarest War Record of Agarest War Zero
I also have Record of Agarest War 2, but the combat was changed and it urked me a lot, and haven't continued past the beginning.
So yeah, I slept many hours on the game, and found it really enjoyable. Though, the true definition of "grind" comes at the late/end game if you're going for the true end. There's some mega bosses you have to kill, and you have a lot of level grinding to do to kill them. I believe you finish thee main part of the game at level 70s, but you need to be like 250-300 to kill the final bosses for the true end. I left off in my second playthrough around 200 before my Xbox broke.