Nordost Blue Heaven Vs. Heimdall 2 speaker cables

I currently run a pair (6') of blue heaven speaker cables and have an opportunity to trade in my speaker cables for the Heimdall 2. I would get $600 as a trade in, bringing the Heimdall 2 down to around $1300 USD and have a couple questions.
1. Is this a worthwhile upgrade
2. Is it a fair trade-in price
3. Should I consider another brand of speaker cable.

My setup is:
MC275 amp, VTL 2.5 pre, Sonus Faber Olypica I, Auralic Aries streamer, Auralic Vega DAC, Clearaudio concept turntable. Nordost cables throughout. I typically listen to Rock, pop and some alternative. 
Thanks