I find this change frustrating. I've been reading and occasionally commenting on HN for 4 years, and I'm still not able to fully participate. I haven't yet reached the magical karma number needed to "earn" the downvote button, so I can't help moderate except by flagging.

Now, with this change, it's extremely unlikely that I will ever achieve the ability to truly participate. It seems that if you want comment quality to improve, then maybe it's a bad idea to even more tightly lock out people like me who would happily downvote bad comments or endorse good ones.