Tried out the Beta versions a bit a few days ago, but made no immediate decisions. Today, I spent a couple hours on the site and now have these impressions:
1. Very slow page loading, as others have noted. Accept your explanation that this is temporary while tuning is in progress (hope it improves sooner rather than later!)
2. Also agree with another poster that the "Recent Forum Activity" panel is not useful to me when I am reviewing anything but the Forums section of the site. When I am reviewing the File Library, I could care less about Forum Activity and would rather use that space for a wider File Library text area. @JSkorna, I am also unable to locate the "arrow" which will remove that panel with "one click"...more details, please?
3. Forum thread icon colors are too similar for these old eyes to differentiate easily. The "read" vs "unread" colors should be more distinct. Also, I am unable to discern any difference between the icons for "Hot with unread threads" and "Hot with no unread threads". They appear to be identical to me, even in the legend at the bottom of the page. Shouldn't the "no unread threads" icon be much dimmer?
4. I prefer the "white" version... the "blue" version makes the text more difficult to read (lower contrast) and the "photo" version is too busy (distracting to the eye), in my opinion.
Otherwise, I see no difference in navigation or operation of the site, from the user perspective. Thanks for your continued support of our "hobby" (addiction).