We've long had the ability to create a Comparison Graph, but now we've taken it one step further.
How about being able to compare stats on the fly?
Now you can, with the Drag to Compare feature.
In the Graphs View, click on the graph of choice and drag it over to "drop it" on the one you want to compare it with, as shown below. Make sure the "Drag to Compare" turns green, then you can "drop it" on the graph.
You can also hide or show each stat by toggling the legend.
And when done either close the graph or cancel overlay (also shown below).
Pretty cool hey?
NOTE: This does NOT work via the Dashboard. You must load the graphs in Graphs View.