Congrats on the new amp, but yo do understand this is a amp first, 6 watts and a headphone amp second about 1 watt as far as I have learned from the site person.
Not saying that its not good or a bad thing...just want you to know that this is not a 6 watt amp for headphones, kind of like the new Schiit Lyr which is indeed 6 watts.
I am looking at the MP 301 as well, even though it does not have 6 watts to the headphones etc..
For that part most headphones if cranked open on a 6 watt amp will self destruct!!
All the best,
Let us know when you get it and how it sounds!
All the best