I have some experience with the original versions of Heimdall and Frey. The Frey was definitely a big improvement over the Heimdall, smoother and more substance. They were both too thin sounding in my slightly warm-side-of-neutral system so neither was worth the money in that respect. I put Frey 2 throughout and never looked back. They are balanced from top to bottom and to quote a cliché "Makes the old Frey look broken". I have not heard the Heimdall 2.
Heimdall 2 vs. Frey 2
Most retailers, reviewers, and owners have a somewhat similar consensus that the Heimdall is the sweet spot and best value in the Nordost line (though I understand this is is system dependent). I've also read from several different owners that the difference between the Heimdall series 1 and the Frey series 1 is not that great to justify the increase in price. Has anyone heard or have any thoughts on the difference between the newer Heimdall 2 vs. the Frey 2? Either in speaker cables, interconnects, tonearm cables, or power cables?