What have people found sounds appreciably better than a Bluesound Node2i/Vault2i?
In brief, my CD player, a decent but not exactly high end Marantz SA8005, sounds significantly preferable to my ears than the Vault.
I know some of what’s out there - external DACs, ND5XS2 et al - but would like to know what others’ thoughts and experiences might be.
It depends what your (p)reference is. Any Naim streamer is a huge step forward. Against theNode 2i, I know a lot of other streamers in similar price class I would prefer.
To my ears, the BlueSound is tuned on the safe side. It must appeal to a huge potential buyer audience, and must be enjoyable even when used for background sound with other activities. So, it must never offend, nor excite.
To my ears, it lacks character: it reproduces music without fail, but the reproduction is rather bland (music for shopping malls) and as a result boring.
YMMV.
I’ll echo the comment above and add that with your setup(SN3) I’d aim for a ND5XS2 at a minimum.