I would like to be able to change the displayed time range within all Perfstack widgets in a single view. One of the limitations with Perfstack is how the graphs are arranged within a perfstack project -- they are arranged top to bottom. This doesn't make for great dashboards. To get around this, I created multiple individual perfstack projects, and dropped them on a new summary view. This gave me more flexibility in the arrangement:

The only downside here is that to change the timeframe under analysis, I have to click through each perfstack widget and change them individually. I'd love to see a method that would allow the timeframe to change for all perfstack widgets at the same time.
I realize that in this particular example, I could combine the charts in each column to reduce the number of widgets for which the time would need to be changed. But it would still be nice to have a single point to do this regardless of how many perfstack widgets are on the dashboard.