The translator's note indicates that this is an updated translation and makes some notes about the faults with the prior one, and specific changes made (particularly with regards to the German Mensch). I haven't read the previous translation so I can't comment on it in particular, but if you tried reading this before and didn't like it, I would suggest giving this new translation a go. Unless you've tried David Horrock's translation for Penguin Books, in which case, this book is just Not For You.
This edition also comes with loads of footnotes explaining the numerous literary and otherwise references throughout, which does a lot to elucidate the nature of the titular character, Harry Haller the "Steppenwolf."
Hesse is one of my favorites. I feel like most disaffected, cynical youth say that, but he really is. Siddhartha is one of my all-time favorites (if I absolutely have to pick a favorite book); it definitely left a mark. I've also read Demian, which is okay, but I have yet to tackle Hesse's masterpiece, The Glass Bead Game.
I'm still early on into the book so it's hard to comment otherwise. And again, as with many classics, I don't often feel up to the task of a review. I just like to keep track of what I'm reading and generally what I think about things.
What are you reading?