Well, I just finished Demon's Souls (took me about 50hrs) and while it was definately hard in the beginning, once I got the controls down, forged some decent weapons, and built up my character, it really didn't give me too much trouble.
Don't get me wrong--I probably died 100 times over the course of the game--but at least half of that was learning the ropes in 1-1.
I may get a lot of flak for this next comment, and some may not even believe me, but I beat almost every single demon boss on my very first try (some of them were tough, mind you, I had to heal 15-20 times over the course of the battle, but I won). I died a lot more often by the hands of regular enemies, or probably even by falling off cliffs, than on bosses.
I was surprised to find that I was able to use 1 sword and 1 bow for 95% of the enemies. With all that I had heard, I thought each boss was going to take a vastly different stratgey, but they didn't. Were pretty much 2 varieties: melee and ranged. Did anyone else have this experience?
By the way, not saying Demon's Souls was easy, it was totally oldschool and brutally kicked my ass at times and I loved it, just surprised about the bosses.
EDIT: Forgot to mention, I did have difficulty navigating a few of the levels, namely the prison and the toxic swamp.