So mine was crawling as well, with what I thought were the correct settings for dsfix. Well, under Framerate and a bunch of scary warnings (which is why I didn't change it in the first place) is an 'unlock the frame rate' option. I set unlockFPS to 1 and the game runs beautifully. Serious night and day difference.
Anyhow, I'm just now heading into New Londo ruins. Ornstein and Smough gave me trouble, but I pushed through and felt I learned a bit about being more aggressive in combat. Also, in Demon's Souls I never once used parry/riposte, in Dark Souls it is my bread and butter, yet the first time I spent time to learn it I was already in Sen's Fortress. Such is life as an undead..