Yes and no, I'm not married to the coaster, but since the hubs can be had with them, my parts count goes way down by having a single brake integrated into the hub. I mentioned the brakeless fixie more in regards to their simplicity than their style.

As for the hub weights, I was going by the weight difference between the shimano nexus 8 and the Inter-3 listed at Harris Cyclery. I haven't really researched any of the SA's or other hubs yet.