The Heimdall Series 1 does not sugar coat anything, if you system has some edge, that will show through. I have read that the Series 2 are a bit more forgiving.Agreed +1 - Did an in home demo and the Series 2 are also more liquid and warmer sounding. My Tyr 2 Ic's should be here tomorrow.
But I have the Frey's at at times (especially with recordings that do have an edge) The Eco3 helps. Not earth shattering but it does help a bit. Better recordings then sound better. That being said I only treat the cables every month or so.