Nice to hear your impressions -- I've also been hankering for a 12 fret but haven't gotten my hands on one of the newer 812 12 fretters yet.
However, I did land an 812ce yesterday, which I am evaluating.
Like you, I find it to be a beautiful instrument, very well made. Also like you, I think the tone is really nice - but doesn't quite have the "fullness" I was hoping for. As I mentioned in another post, my GC8 from a couple years back has a noticeably richer/fuller tone, although some might argue it's not as articulate/clear as the new 812ce.
The Taylor Road show is coming to town here in a couple weeks, hopefully they will bring a 12 fretter and an 814ce so I can do a little comparing! In the past, I always thought I'd get a "bigger sound" with the 814s but it never seemed to me like they sound the emitted equaled their body size. Maybe the new ones will be different.
Looking forward to hearing more reports of how you are adjusting.