Those RPGs really vary, people fucking love Diablo 2 yet something about the way it looks and plays annoyed me, so I always preferred Arcanum as my main isometric RPG by far.
Regardless, they all have a lot of random bits of depth and detail that can take a bit to understand, for me that just makes me appreciate a game more, the deeper it is the better and more enjoyable I'll probably find it.
But if your attention span or patience isn't great then those games will probably never be your kind of thing.
I have 1080p monitor and the default player takes up like 2/3 of the screen so I always thought it was a decent size.