Zach emailed me this feedback:

Hi Gretchen,
I used the test forum and it seems really good and performant (I can't wait to subscribe to them using RSS!)...
A couple of comments:
1. Registration was not intuitive, I struggled to figure out which fields were required etc. Also you should indicate why you are requiring the image letters to be replicated and that they are case sensitive.
2. I find that 90% of the time that I go to the forums I am going to search for a particular solution, so a simple search would be valuable on the front page.
Other than that good luck on the migration and I look forward to using the new and improved forums.