Both Caledon and New Babbage are steampunk communities full of lots of creative inventions by Second Life's steampunk community. Both are cool. But somehow I find the suburban layout of Caledon as taking from the experience. All the pieces, each pretty cool in itself, does not work together. You look like you are at a conference for steampunk inventors. Why New Babbage, which is laid out as a city and is often hard to navigate feels like a community.
Community is more than just a network of people on line with shared interests: its also a feel of a community. In something like Second Life its critical to build structures that work as communities. Cities build community, suburban space tend to isolate people.
Walking around New Babbage you are likely to encounter someone and make a new friend, the city streets channel people in to hub spots. A grid layout like Caledon tends to isolate people to their own little square.