I was faced with the same decision as you, but instead of going with LK85/Wakonda, I went with the LK140/Kolector. I could not hear a great enough difference between the Kolector and the Wakonda, but could between the LK85/LK140. The Kairn was more than I wanted to spend and I am expecting a refresh on it soon.
I upgraded the above from a Majik and heard a huge improvement in sound quality. Even the 85 will be a big improvement over the Majik. I tried running a LK100 and using the Majik as a preamp which was an improvement, but still found the Kolector better.
I have ran my Genki with and without the Kolector and, to me, it always sounds better through it. It sounds much fuller, more dynamic, and simply more fun. You loose quite a bit of volume too. My wife thought the same when I A/B it for her. To answer your question, it is not critial, but you will get a lot more enjoyment out of the Genki if you do.
Good luck.