I'm not even that definite...Expansive's +3 health is a lot better than it was before. Some keen eyes also mentioned the bonus to producing granaries and harbors...
If I had to pick a least useful trait, I would say Creative--sure, the early land grab is great, but what about the other abilities? Quick production on theatres? They are already quick! Colosseums...maybe, but those are my last ditch happiness resorts, right there.
And, if you happen to get writing quickly, you can expand your borders by whipping libraries and monuments. Or you could get Stonehenge.
And anyone who voted Spiritual...seriously, you guys are missing out. Try having all your cities with your state religion building buildings with Organized Religion, then immediately switch to Vassalage-Theocracy and produce troops everywhere. Then, once they are all completed, switch back to, say, Bureaucracy and Organized Religion. Try switching your government--load up on specialists, then switch to Representation to max out the bonus. Then, switch back to field workers, and go for a different government.
It's a lot of micromanagement, but you have so many more options as a Spiritual leader than you do as a normal one...it's a strong trait when used right.