I like the additional filtering in the experimental interface, for example to switch between "All" and "Hot". I could see that being quite useful. Though the experimental page has too much whitespace for my liking - I can see 5-6 stories on a page vs. 10 or so on the HN style page.

It would be great if it saved my preferences (Sort by, date range) since I usually end up flipping those values to the same thing.

One minor annoyance is "JavaScript" being picked up when I search for "java". Would be nice to have the option to search for whole words.

A very minor annoyance is usernames are treated the same as text in stories. If I search for 'IBM' for example, I'll get all stories submitted by user 'IBM'.