Always scope for a change at some later date.
I quite like the idea of an m6i and nearly bought one off the bay before doing the sensible thing and demoing the M2, 8xpd and XS. I think Cno is right though, the next are to look at is probably the source, good though the dacmagic plus is, it's probably a bit out of its depth (see what I did there).
Right now I am really enjoying just listening to a random playlist, some new songs tyhat I've not played before and some very familar ones and all sounding fantastic musically. I just can't quite decide whic filter to set the DAC to, I think I prefer LIN1 which gives a slightly glassier sound maybe but the imagery and "focus" is just that bits sharper. I'm not going to make any more changes though for at least a couple of months, even if I wanted do / could afford to because the D18s are clearly not fully run in. I was listening to Achtung Baby earlier, and there was a depth and slam to one of the tracks that I have never experienced before. This is where the M2 excels I think, it has massive amounts of sonic grunt which are great for rock / pop. I suspect finding something super smooth with the same amount of fizz and energy is going to cost a fair bit more.