Personally I found it a bit hard to get a feel for the data because the timescale isn't very evident until you hover or click on a box. I found that putting it on a dashboard with a Year-Qtr selector sheet to highlight a particular quarter helped that. All depends on the analysis you are doing and how well you know your data, I'm sure.
One interesting thing is that the highlight action doesn't work in the version 8 beta. I initially opened the workbook in v8 and wondered what you meant. I'll report a bug to the beta team.
That is a good suggestion for helping users identify the quarter they want to see vs. just selecting a particular box (say the worst quarter for Appliances) and seeing how the other categories performed during that same period. Thanks!