How do Digital Amps Mfrs. compare in sound?

I am so excited about all the reviews of various digital amps out there. I just know this is the future of audio because the value is just too irresistable.

But, there are so many companies out there: PS Audio, Bel Canto, NeForce, Wyred, Spectron, etc just to name a few. To compound the issue(s), the modding companies like Cullen Circuits are upgrading and modifying digital amps. So are there differences between these companies products' sound or does digital equipment sound homogenous? Where does the biggest "bang-for-the-buck" lie when it comes to digital amps? Has anyone directly compared any of these digital amps to each other?