Like many others have said, the new customisation is amazing and really helps bring home the look and feel of the Nightborne closer to how they were originally envisioned in Legion. Combined with the ‘heritage’ weapons being available on the time-walking vendor, we’ve been pretty lucky. There’s just a few things more that can tip the quality into perfection.
The jewellery is by far the most impressive and varied addition. With an addition of bronze and the dull greeny-silver colour used by some NPCs to accompany the new gold and silver colours, this would fully complete the metallic vibe nightborne have. (Top two below)
More importantly to nightborne, however, is their magical side. Unlike the NPCs, players have almost zero options regarding such; lacking the magical hands, mana-infused hair and glowing tattoos that can be found on various nightborne mobs. Despite the new tattoos looking brilliant, they are hard to see without correct lighting – something that could be amended by having a toggle for the luminosity of their glow, from its current dimness to a more vibrant purple or blue. As for the magical hair, something like the Dark Iron and their fiery highlights would work wonderfully.
Finally for raw customisation is eye colour. We are still stuck with just one option, even lacking the purple tint that almost every nightborne bar the felborne have – I’m pretty sure we had this tint at one point, but lost it in an update.
Less to do with the imminent customisation is changes to their heritage armour. Of-course there’s the secondary heritage armour variation in gold and red just sitting around in the files, which we would all love to see. (Especially now that we have golden jewellery to match it!)
In a more involved manner, there are several fixes that can be made to the heritage armour as it is. As already posted here, the male chest-piece could use an exposed chest to show off the tattoos beneath – but there’s also quite a large flaw in using the heritage pieces for transmog that this picture adequately shows:
With the chest stealing all 3D geosets including the robe piece, it is impossible to have a robeless look while maintaining most of the heritage parts.
These are the few additional changes that would really complete nightborne for me, barring slight model edits for the male that other posters have gone into in greater detail!