Moodlerooms Advanced forums can be used at http://demo2k12.moodlerooms.com/.
Organizations interested in Joule features and possible hosting can also request a 15 day trial of Joule as well. The 15 day trial will be their own site to play with where the above link is like demo.moodle.org and gets recreated every 12 hours. There are also several videos on Youtube just search for advanced forums.
Both of these options provide a demo of all of the features we are suggesting be part of Moodle core, activity grading interface, advanced forums, alerts and streams, and outcomes (as of July 13th when we release it to our clients).
Because advanced forums is a separate forum type we have never recreated the forum search functionality or the display posts in the user's profile. This would all come by moving Advanced forums back to a core forum. As I said the migration would be as simple as search and replace hsuforum with forum in the code.
Nothing currently exists in Advanced forums for user notes beyond adding the notes block to a forum. https://tracker.moodle.org/browse/MDL-39707 lists all the features that have been added beyond core forums with the exception of manual grading through the activity grader interface. Which as Martin stated is not included because AGI is not in core.
As for the lose of the reply I agree that is the one feature that Forum NG has the I want to add to Advanced forum's nested view. It is my opinion that if you combine Forum NG's inline reply with Advanced forum's Nested view (AJAX load of forum and replies on demand) you would never use any other forum view unless you were visually disabled.
One thing that both advanced forums and forum NG fail at is an accessible view of the forums. I have seen nothing from OU in this respect for forums, but I know we will be implementing this functionality by August in advanced forums. Again as per the ticket above the design will be based on http://blog.bargirangin.com/2013/03/a-model-for-accessible-lms-discussion.html. I still need to get a public specification for this, working towards this by the first week of June. Multiple display options to me is a huge advantage of advanced forums over forum NG. A user is allowed to pick a view of the forums that is most productive for them.