Finally got the store to work. Heh, there was a poison pill built into the new file that forces you to use automatic date/time settings or it won't load. I've always had mine set four years ahead so that the scrolling ad banner in the upper right of the XMB would be disabled, but I guess I'll have to stop using that trick.
Overall, I liked the snappiness of the original store. It always came up in seconds, and I was comfortable looking for stuff I knew I wanted to check out. This new one takes awhile to load as many have noted, and there is some lag as you wander about the store.
However, I do like the filter options it now has, though they should've allowed us to use multiple criteria simultaneously, i.e., "show only new+PS3 releases" instead of one or the other). The search box is infinitely more accurate.
Design wise it looks decent enough, icons aren't too large or too small for instance. Finally, I wish they kept the red PS shopping bag icon for stuff you already purchased while browsing. The plain text in its place forces you to focus on it instead of being able to merely glancing at it.