I like this. It's simple, easy to read and follow and it's not overly distracting. It just doesn't have that pizazz i guess.
Completely aside, this is an awesome idea for a website and I'm looking forward to adding a couple records on here.
I personally believe that this is a well laid out design. You've taken simplicity really well, especially in the content area. But I do believe that the header design is lacking. A site like this deserves better graphics than this, but excellent design nonetheless.
Not a bad concept here but you need to make it more engaging. You need subtle details that helps make things look more finished (Borders, shadows, gradients and such).
The site looks pretty cool, but it's a little flat and almost looks outdated. It took me a few seconds and some looking around to find out exactly what the site is about. You may want to consider making the "What is URDB?" larger and enclosed in some type of container to make it stand out a bit more.
Other enhancements to consider include:
-try adding a slight gradient from white to transparent in the header to add depth and make the title pop a bit. This will also help with the readability of the title.
use some graphical elements to help separate each record title, description, criteria, and read more link.
add some more color to the tabs under popular records.