I wrote a script that creates statistics out of the demo filenames (demos formatted according to the current cg_autoaction format, not the older ones or manually renamed demos).
Its pretty straightforward so i will just show you what you get after running it... http://pastebin.com/LHZZUTVd

Here is the same output formatted for the post:

So currently it gives out how often you have played each map in each mode and and your duel opponents (that you have played more than 2 times)

Thought these infos might be interesting, but i have no real "use" for it. in the future i want to implement some more features like plotting the data in a graph or filter for certain players etc...

To run it you just put the qlstats.exe in your ql demo folder and check stats.txt. if you dont wanna run a rnd.exe (i can assure you its safe) you can also use the attached .lua script (you need to be able to run lua scripts obviously) and here is the source code. (horrible coding, i know :D)

Please share your stats.txt and report any bugs you encounter (currently there are some issues with "-" in clantags and names cause it messes up my string identification)