hakunamakaka
1000+ Head-Fier
For me, that's the easy part. If you ask most users here, I think you'll get the same answer. The harder part is how to find time to go over the music selection again.
I guess that would be not to bother and go with DI-20HE. If there is really an improvement that should be the right route, but I doubt that there will be owners of DI-20 and HE version for comparison :I I'm not even confident of how much of the goodness it can bring over IRIS DDC, but that one is out of the question cuz of compatibility issues with mac OS