Well, what can I say?
I didnt run any benchs either but as far as feelings go I feel CM11 faster and smoother than any sony iteration I have tested, granted that I didnt test KK.
I guess it is a matter of preference indeed, I got a new tablet when changed to CM11 but I wouldnt change my Z1 rom as I dont think there is any advantage to it.
Nonetheless, if anyone care to try CM11 or AOKP I urge them to do so!
Motorola Timeport (First Mobile) > Motorola V300 (First camera phone) > SE W800 (Change of pace) > Nokia N95 (First Smartphone, best symbian ever) > Nokia N97 (Worst phone I've ever had!!!) > Nexus One (Android saved my life) > Samsung Galaxy S2 (Nice piece of hardware) > Samsung Galaxy S3 (Nice phone, a little too fragile) > Sony Xperia Z1