I've had the AQ Panthers and Cheetahs ic's in my system. Whilst I never did a direct A/B comparison with the DBS system on or off (not exactly a well controlled study), I can say that these cables never needed any burn-in time. They sonic signtature remained fairly constant with time, which I like.
I wish I could comment on the sonic improvements of the DBS. They are nice cables, generally well priced given and engineered.