It depends on what kind of gamer you are. Are you a button masher, and did you enjoy LotR: The Two Towers, by EA Games? Are you still thinking to yourself, X, X, /\? Are you bad at math? Then Proud Mode is the mode for you.

If you enjoy minigames in general, or have a strong case of perseverance , then complete the Journal. Synthesis hunting and the Paradox Cup also require leethax math skills: you must have been in at least Algebra One by 12th grade.

As for your inquiry about time, it took me 28 hours on Proud Mode to beat the game. It took me another 20 to finish the Jiminy Journal. Since my expectations are not other people's, we shall move on. It'll probably take you less time to play through the game again, and not to mention, you can skip scenes, and things will go faster, seeing as you have already done it once before. Of course, if you already have most of the Journal completed, then try to finish it.