The SHD is a clever device, and it opened my eyes to the power of room correction. I had been using REW for a bit, but I wanted to try Dirac in a new system I put together. The ability to save a few different presets and calibrations was great, and whatever magic Dirac does was pretty astonishing sometimes. I ended up with a favorite Dirac preset that only corrected below 400Hz, calibrated to a specific listening position, but you'd think it changed the entire spectrum, and added effects, and ... who knows? It was a pretty startling transformation. I had another for a larger audience, and some other slots just for experimenting with bass enhancement, etc.
The only reason I'm parting with this one is because I've redone the room I'm in, and have moved a Mac in as my primary audio source. I'll be running everything with software on the Mac now, so I no longer need the SHD.
There is a short learning curve for their sometimes clunky software logic, but it's already been improved with the new control panel.
I already miss the remote control. Quick volume changes, mutes, and turning Dirac on/off...from the couch...got me spoiled.