Finished up all the quests on Dragonspine but the map says 90% completion. I am missing two of the tablets for the secret door, so that's probably it. Gonna have to look them up because I thought I was fairly thorough. Anyway, I had a good time with the new content overall. I found the 'level' to be very well designed considering how relatively small the landmass is compared to the rest of the current world (exploring the inside of the mountain wasn't something I was expecting at all for some reason lol).
Shame I have no one to use the Event Sword for, though. I haven't used the Traveler since the first week of the game lol, and Qiqi has been benched so the sword is just collecting dust while my squad melts enemies anyway. Also the Quest Spear, because I have a 5-star that is better. I wish they gave options for that quest, because I'd rather have a new bow for Fischl or Venti.