Their assembly is reasonable at a few cents per solder joint. I am pretty sure the machine they use is a hard working guy with a soldering iron though. I used it on a small project because they can put down surface mount passive components for less than the cost of the shipping I would pay mouser.
If you can live within their parts library there is no reason not to use it.
If you can live within their parts library there is no reason not to use it.