ok, After some fairly extensive listening I am keeping the ac cable plugged into the Shunyata research Hydra PC. My observations were the following:
Direct in to the wall, the sound was much bigger but a bit raw. Bass response was deeper and the details were more acute. But there was a definite edginess on the high end that left me listener fatigued.
Into the Shunyata produced a lot less edginess and a tighter but more musical presentation. The bass was a bit more subdued and the stage was smaller but still very involved.
In summrry, it's like riding a horse bareback or with a saddle. It seems more exciting when plugged directly into the wall but its a lot more comfortable sounding when plugged into the Hydra.