Sure, but set your expectations appropriately low. I love Dark Souls a whole lot but I just can't stand whole levels in Demon's Souls. I imagine it was easier to overlook the glaring problems in Demon's Souls when there was nothing else like it, but now that it's so vastly improved...I dunno, I'd rather just keep replaying Dark Souls. NG+ in Demon's is completely stupid and brings the really cheap enemies to greater light.
That being said, there are cool things about it that are worth seeing, so go for it. Also, I felt like Dark Souls was more foreboding and scary but other people seem to think the opposite? I dunno. The prison was pretty neat.