Your ps is absolutely right - I was very conscious of that and I've only really started to get to know 2 of the sets I've bought, let alone the N3... thanks for that, you've put the brakes on my addictive urge and saved me from some challenging discussions!
I am debating selling some other headphones in the new year, I've more Bluetooth than I need and generating some cash there would be a perfect justification.
Just a quick personal opinion :
if you want an end game on IEM, ier-z1r will be a good choice if money isn't an issue.
z1r provides the smooth / detail / staging of M9, on top with one of, if not, the best DD bass u can get.
The fit issue of z1r can be fixed with customized tips (ex. adv)
I don't know what your setup is, but z1r is hard to drive well.
(Wm1z only gives 80% of z1r's potential, missing 20% is on bass control / speed )
I currently own ier-z1r, m9, xelento, se846, driving with Wm1z