Yes I think so. I've been trying out the MX/Fir 0/M15 this morning with various vocal tracks. There's something slightly 'off' about the Fir 0, especially with female vocals. Can't quite put my finger on it but compared to the MX/M15 there seems to be a bit of glassiness in the trailing 'breathy' edges of some female vocals. Small margins, I know, but these are the things I get obsessed with when closely listening and comparing. Pity because Fir 0 bass sits right in the sweet spot between the MX neutral-warm and the M15 warm-powerful. I guess if female vocals weren't my go-to I'd use the Fir 0 more regularly. Really nice to have the choice of all these sound profiles and signatures with the same IEM. The Nio is quite exceptional really.
Also been switching between Xelastec and Spiral Dot, with the former winning our for focus and sharpness and the latter for more organic, more diffuse/wider, gentler sound. Two very distinct experiences depending on the tips. Another feather in the Nio's cap for sure.