Well I finally ended up getting my NU4-6K, the Polk TSI A9 sound a lot better running off that amp then the XPA5 there were attached to for the last 8 months.
Wife actually came in while playing an MP3 and she asked if I had everything hooked up which meant my 15 and 18 Marty's and I said NO. The extra power is noticeable. The amp did have a bad hum, but tracked it down to ground loop and just hooked up a ground wire to DENON AVR strangely the Emotiva did not have that issue.
Who needs 4K?... just go see your optometrist.