So I finally beat the game (well, just the main story). I've been playing it in short bursts for like the past 6 weeks, 'cause it was so easy to pick up wherever I left off. You can save anywhere, and maps are divided into manageable areas. I'd just clear an area, save the game, and turn it off. Later I could start it up again and clear the next area. And so on.
First of all I want to say Joker 2 really is way more fun than Joker 1. The pacing is faster (monsters level up faster, you meet/acquire new monsters faster) so it always feels like you're making progress. Grinding metal slimes also seems easier. In my opinion Joker 1 got boring after awhile, just running around the same maps. But some of the new features in Joker 2, like giant monsters, sunny/bad weather, and respawning plants/ores/chests, help liven it up.
Ultimately, the focus is still on building up your monster party, but it seems less monotonous and more exciting in Joker 2. If you didn't like Joker 1, you should still give Joker 2 a try. I didn't like Joker 1 either, but Joker 2 has me hooked.