I have listened to the dcs rig both with and without the Apogee Big Ben master clock, which serves the same purpose as the Verona. The difference is not subtle. The soundstage is slightly wider, more transparent and better organized. Instruments and voices are locked better in their specific location. There is just a more organized character to the soundstage.
Also, as another poster stated, there are improvements in resolution and timing. But it is the soundstage improvement that hit me first.
At roughly $1500 it is a worthwhile upgrade since it places this rig at the pinnacle of CD playback.