The musical scores for both these games are phenomenal. The thing I really dig about Demon's Souls is each piece has a continuing motif. You can hear those eerie four notes or so in every piece of music in the game. That really made the game for me. I'm a sucker for good music. In Dark Souls it's harder to pick out a motif, although the intro piece is very reminiscent of its predecessor. I've yet to hear any music past the Golem Knight, so I can't tell if Dark Souls is keeping the trend. So far, the score definitely sets the mood for battle/cowering in fear. Either way, good stuff.
As for PVP. Drathbone, what is your build? And what equipment are you using? Are you better for ranged battles or up close? I personally do not fare well against NPC enemies that have high dexterity; simply because I use a heavy weapon with a rather sluggish attack speed. So, try switching up weapons. Also, I found a miracle called Tranquil Walk of Peace that will over burden your enemy, causing him/her to move very slowly. You do need to have Faith at 18, I believe. I can't really add much more. Good luck!