Nordost Valhalla 2 Speaker Cable

You'll be very happy with your Valhallas. I had Valhalla many years ago, and it's a great cable. It's top card is transparency, and it has that in spades.

I have Tyr 2 now, and have for years now, and it's a fantastic cable as well. I am guessing your dealer wants to do the burn-in because Nordost takes hundreds of hours to burn in. One time, I had a brand new pair of Frey 2, and it took them weeks to break in. 300-400 is standard burn-in time for Nordost, and it will sound VERY bright  before its burned in. In fact, so bright that you will not want to play music loudly. I remember listening to a Supremes Anthology, and it (the Nordost) was SO bright, I couldn't listen at any volume. It actually hurt my ears, and that was the first (and only) time in 40 years that a cable was that bright.  After it burned in, it was great.

Give the new cables additional 2-3 weeks of play time after the initial burn in by upscale and enjoy. 
I am hoping to try the Valhalla 2 speaker cables one day but that won’t be very soon 

As to Nordost lines and mixing with other cables…

I use Frey 2 power cords on DAC and amp. I’ve tried a lot of different power cables over the years, these are the best do far. Looking to try Tyr 2 this year. Interconnects are Tyr 2 XLRs. Again, I compared a lot of interconnects and these sound the best to me. Speaker cables are Audience FrontRow. So mixing and matching is key. The system sounds ridiculously good. 

I received the cables on Monday but unfortunately can only listen to them on the weekend. I did not go in for the burn in as I wanted to get my hands on them as soon as possible and Sean (SMO) from Upscale audio said that it will be another week and a half till I get them. I have to say Sean is a great guy to deal with. He kept me in the loop all the way. 
Now I am waiting for the weekend to listen to the cables and will let the system break them in by playing them. I like to listen to the cables while they are breaking in and enjoy the subtle changes occurring in the cables. I did the same with Frey 2 speaker cables and loved it. I maybe posting a review when cables are burned in if all of you are interested. Thanks for reading my posts.

Awesome! Looking forward to your review! 

The unfortunate part of listening to burn in as... at least when I was working it could take nearly a year to burn in at the rate of 45 minutes per day. 

I just got myself a modest system that I hook up and leave on for a couple weeks to burn stuff in.