It's definitely up there as strongest debut, and solid with 6 issues almost ready for the first trade. Sad to see there will be a hiatus but at least it's fairly brief. Hopefully people will buy the shit out of trade 1 and pick up the monthly from then on to strengthen the book.
Tough to compare to BKV's other books, because it's only six issues.. but through the first arc of this, Y, and Ex.. I think this might be my favorite opening for the sheer amount of world building done in these six issues alone.
I think overall, Y: The Last Man is still my favorite thing of his.. but if he continues with this at this high quality, this should easily top it.
And honestly, I'm surprised we had six issues without any major delays. I remember Ex Machina was constantly delayed near the end there.