You didn't make a mistake moving from MG 3.6 to Wilson's as they are one of the few box speakers that are as fast and precise as the magnepans (i've owned three sets of Magnepans and upgraded to Wilson Watt/Puppy 7's), and now you get the capability to do dynamics!
I have run Transparent Reference XL (and with XL for the cables I couldn't afford)with outstanding results. Never tried the Valhalla which I heard of similar caliber. They might be a little dryer on the upper/mid than the Transparent on the Wilson is what I remember from other comparisons.
Spend time using the Wilson method of setting up your speakers (without the spikes so you can keep moving them around) They are really precise and 1/4" can sometimes be the difference between Bliss and Excellent.