I found my headphone nirvana several times. In general, I felt that I could be completely happy with Stax SR-003 (backed with an analogue source, back then it was a Museatex Bitstream with upgrades); Stax Omega 2 (with an an upgraded Museatex Idat-44 Mobile and much improved SRM-727 amp); Smeggy Tamboti Thunderpants (while another thunderpants he made was very bad sounding, so there is too much variability); SR-X Mk3 Pro (only with said Bitstream; with other sources, it showed too many of its flaws); I have heard the SR-009 and it's another end of all phone.
Stax Lambda with a beefy, analogue source are also an end of all headphone.
Lambda Nova Signature aren't an end of all headphones: too low resolution compared to the other Stax... too blurry.
They are all different price tags. The SR-003 has its limits in deep bass and comfort, but what it does is still magical and so addictive, so right. It could have easily ended all for me. It can still do that.