Nice! I notice the neck appears a bit longer than in your original concepts... any particular reason beyond aesthetics? Personally, I kind of dig the shorter one.
Yes, it is a touch longer. I just felt it better balanced visually when you factor in the addition of the nacelles when in place. And I should get something posted with the nacelles in place soon. Then all the major components will be done and it will be a matter of detailing.
Note, though, that this remains stubbier looking in general than the Pike and Kirk era ships that will follow while still retaining some element of grace and subtle curving. I tried to resist getting too blocky and chunky looking. I also feel I've established something of a lineage from the star clipper to this and then to the Pike/Kirk era designs.