I hate to get all meta, but as of this writing the parent comment has -2 points. I understand that comments that just say "Interesting :)" are frowned upon on H

I hate to get all meta, but as of this writing the parent comment has -2 points. I understand that comments that just say "Interesting :)" are frowned upon on HN because they add no information. However, in this case the commenter is the OP. He's expressing thanks for a lengthy, informative response. "Thanks for responding, that's an interesting perspective" is not a class of comment that deserves downvotes. It's completely appropriate. (Update: The comment was deleted as I wrote this.)