Issues:
1) Requires too much effort (rolling over hover states) to dig out information.
2) Pairing circles and rectangles as a node make it hard to parse when your eyes are scanning the page. These shapes don't naturally go together.
3) URL's are truncated too short. On the bottom left of the live demo, you see "/account/listi..." twice, and they're actually different URL's. For some websites I can see this becoming a major issue.
4) The rounded circular graphs with the blue and red look nice, but doesn't convey the information very well. Any type of circular chart (pie chart, tachometer graphs, etc.) is not recommended.
Suggestions: I would consolidate the information for each node and show all of the visible and rollover data into a single box. Use varying font sizes, colors, and weights for necessary emphasis. Instead of the circular graphs, use a horizontal bullet graph[1] along the top of each node. Use the bullet graph to display the historical high and low as the bar, and the daily range as the background (or vice versa). This way, the user can scan the page looking at the bullet graphs along the top, and then if something strikes there eye as unusual look below and examine the data.