I'm basically a lurker (I'm guessing I've probably been around for about two years although I've only had an account for about a year). I frequent Hacker News because it's a good technology news filter that keeps me informed of the latest trends without having to sift through link bait blog posts in Google Reader. For me, the enjoyment of lurking has definitely declined with scores being hidden because it's difficult to quickly find valuable comments. I voted for "I liked it better when comment scores were displayed."

I'd agree that comment wars have declined which probably makes it a much more enjoyable experience for frequent commenters. Having comment scores shown seems to encourage lurking and quick consumption while hidden scores seems to encourage thoughtful comments but it makes lurking difficult. I'm guessing the goals of the site are focused more towards commenters/community than it is towards lurkers.