Heh, it's probably in my top five of all time.
I think the whole difficulty thing is a pretty big misconception with DS. The game is tough, yes, but more than that it's demanding of the player in a very unique way. It isn't all about dexterity like with Ninja Gaiden or many other third person character action games, but instead it's about playing patiently and learning how the game works. A lot of times the reason you're dying isn't because of raw difficulty, it's because you aren't slowing down and thinking about what the game is throwing at you. It requires deliberate and well-thought out actions, and because of that it's incredibly rewarding when you finally overcome the challenge in front of you.
On top of that the level design in the game is simply phenomenal (with a few exceptions). The entire world is connected and intertwined, almost like a 2D Zelda game, but there is very little hand-holding, it's up to you to discover where to go and what to do. As you play you'll continuously open up shortcuts that reveal more and more how the world is connected, and a lot of times it'll blow your mind when you first see it.
I could go on and on. An incredible combat system, solid RPG mechanics, innovative multiplayer features, and some of the best boss fights in gaming are all on display here. It's just a fantastic experience from start to finish but I will admit that it's very demanding and not for everyone.
Hell yeah brother, you gaming taste is top notch!! Have you played Demons souls? I started it a week ago and am really enjoying it, I can definitely tell its the precursor to Dark Souls though hahaha!!