Though I've only rarely used the new comment (better described as a reply) feature, I'd say that this is probably the best compromise and solution for those members who wish to respond to subsequent reviews. As we all know, revising a review results in the loss of all "helpfuls", so a revision is not an option for many who keep an eye on such things. A reply allows for members to address a particular review without this loss. I see now that we can now reply to replies made in our own reviews, which is also an improvement. Since I'm of the opinion that reviews should stand on their own, I remain strongly opposed to a thread format for RIA, but again this seems like the best solution to make everyone relatively happy.