I have a Decco, and I was disappointed with the sound at first. Felt that it lacked dynamics, soundstage was muddled, and I wasn't very engaged when listenening in general. Also, my living room seemed to eat bass frequencies, except for in certain spots, where the bass could be heard and felt.
A few things have changed all that: First, I got a pair of Definitive Technology BP8020 floorstanding speakers, which each have active 150W subs built in. I modified my seating layout to place myself in the best listening spot. I upgraded speaker cables to AudioQuest Slates, which improved the sound as well.
But the biggest difference was made when I got a used Acurus DIA-100 passive preamp integrated solid state amp, and ran the Decco as DAC/active pre into it. Bam! Separated instruments, awesome, tight bass, and great improvement in frequency response balance from the Def Techs. The Decco 'warms' the sound just a bit, and the Acurus does the rest- clean, neutral, and smooth/ punchy at the same time, if you can believe that.
By the way, if your room is bass shy like mine, I would strongly consider getting the Def Tech speakers- two built-in subs in stereo are waaay better to me than my old Polk Audio PWS110 sub by itself. They really fill the room with bass.
The system's not perfect, but it's worlds better than when I was running the Decco straight into B&W 602 S2s and the Polk sub. I agree with the reviewers who felt that the Decco's chip amp was its weakest link.