Three months later, I'm back for an update...
I've pretty much beaten Dark Stone a few days after my last post. Well, being honest, I got my game locked up pretty near the end because I sold an item I shouldn't have sold and couldn't advance :) But that's OK, as I had pretty much played through the whole game when it happened.
About a month ago I started playing Diablo I and beaten it. I loved it, so now I can compare both games.
In my opinion, Diablo is pure genius and it's hard to compare it with other titles. However, even though Darkstone has a few rough edges and may not be as perfect, I guess I had more fun playing it than playing Diablo. I Definitely recommend it, even for Diablo fans. What a wonderful little game.