Demon's Souls feels slow, stiff and clumsy. I'd rather play Street Fighter 2010 or something, because even though it kicks my ass just as much, at least playing well feels rewarding.
Oh and giving all the enemies in the stage more health every time you die isn't challenging, it's just tedious.
I feel bad for taking a dump on the game for like the fourth time now, but I ended up pretty disappointed with it. For the most part the game's good, I would probably love it if the combat didn't remind me of a survival horror game.
Sounds like you haven't gotten far in the game, the game gets very rewarding if you keep at it.
The slow combat is done on purpose, it also depends on stats etc