I haven't tried other scenarios from five ordeal, traveler's property is brutal, lost another party tonight.... but Prisoners of the battles is good.
Tale of forsaken land is good for it's scenario and some interraction in the dungeon(which I agree many game dungeon do feel a bit empty), but for difficulty I'd rank it on the easy side. Also the stats on some items are a bit weird, like I'd much rather have a dagger because of it's high accuracy and hitting two time(with your str stat you still deal decent dmg) than a bunch of weapon with negative accuracy. You're also somewhat stuck with the story character, they're usually stronger than your character and give additionnal conversations.
The 'sequel' fix a lot of problem the first game had, much faster battle system by skipping all animation, more class and harder game overall, though if you get one Allied action in particular(you can miss it because quest have deadline), the game gets much easier.
they're great game, I played them more than once but I wouldn't say they're better.
Elminage is the best though