Full, unabbreviated statistics. Search functionality. Two massive issues I had that are now solved.
Text search of your story list is a little wonky. It doesn't seem to search the entire list, but rather only the page you're on. Being able to filter by other criteria makes it manageable. I can remember the categories, and that creates a small enough list to be a single page for the most part. I can find what I'm looking for and see what I want to see at a glance with an acceptable amount of effort.
Likewise, using the specific story option for stories to highlight on your profile doesn't give access to your full story list either. Not a deal breaker for me, but it would be nice if you could choose any three specific stories.
( I'm guessing both of those are something that's already slated for tweaking )
Combine that with the new leaderboards, and I'm feeling infinitely more comfortable with the state of things. Bonus points for the excellent new series functionality.
I do think the leaderboards for each category should be featured as a link "More Popular Stories" right next to the two popular stories on each category's page. I think they'll generate a lot more traffic when linked from there, rather than only from the bottom of the page menu.
Please, at least give us the ability to link an image in our forum signatures. I hate how everybody is neutering signatures nowadays, but I'll sigh and live with it if I can just post an image and have it be a clickable link to the story. That is the final major issue I have with the migration to 2.0