The 3.5dB decrease in volume with DPS off could easily account for a perceived decrease in quality on many speaker systems. However, the obvious point of comparison should be to compare a good profile with DPS ON to no DPS at all.
Regarding profiles in DPS 2.0, there is a selection of test profiles to choose from in the SETTINGS tab for each output category. Refer to this help guide to get started.
Also, if there is a profile from 1.x you would like to try, please let me know and I can convert it for you.
One known issue in this build is Stereo Controls may not be active when you first launch DPS. Turn Stereo Controls off then on to start the effect.
We are projecting the release of DPS 2.0 in mid October. All profiles currently available in DPS 1.2.4 will be downloadable in DPS 2.0. All current customers will receive a full upgrade for free.