An upgrade, I suspect, depends on what sort of gain (s) you intend to seek out.
The Pythion helix in my experience added resolution, depth of stage, bottom end slam, imaging (due to the increased res and detail), and further extension up top. It also diminished the apparent grain of the Pythiohn Alpha it succeeded. By direct comparison the Helix gave more refinement to the end product than did the previous alpha model
and far, far greater rear of stage info
. Meaning it moves you back a few rows from the front, though not far.
I used it in several spots, but found its best suited to either end, and usually not the middle. EG., sources or amps
with amps being its best spot overall. However, it will supply its character to whatever extent, where ever it is placed in the system. Ive even been thinking about placing one on my DAC.
Its a quick power cord. Supplying great extension on both ends, with plenty of resolution and detail, but most noticeably, the depth of stage. Speaking of stage size, that likely will increase laterally and away from the listening position. Placing it some where in the middle of a rig, the rig needs to be fairly refined, IMO, or it may come off sounding bright and or thin.