Several issues were supposed to be addressed on the new site, which doesn't appear to have been done.
Allow a poster to designate the poster they're responding to. Default E Mail notification when you post and for PM response notifications. I know you can set up the latter but it was a long time before I realized and likely some other people are as slow as me. All of these were available on the old site so I have to believe someone knows how to do this. At least I think the first one is the most critical because unless a post is quoted, following threads can get really confusing but the other 2 aren't far behind.
Allow a poster to designate the poster they're responding to.
This would be VERY nice. I know we can quote, but that adds a lot of extra text, especially when you're responding to a long post, why quote the whole thing? The old site used to have reply buttons for each individual response so you could just click those, that would be very nice.