They are both fantastic games, and would highly recommend playing demon's souls. what everyone says is true, just 1 more thing i would like to add, I found that dark souls' equipment system (can hold as much as you want), encouraged one to experiment with weapons a lot more. i played around with long swords, curved swords, axes, spears, etc. whereas with demon's, i always stuck with my trusty falchion and beefed the hell out of it.
Loved playing as a Wanderer in both games. I enjoy being nimble on my toes paired with destructive power, than being a heavy holding some mammoth weapon that makes the buster sword look like a pencil...







