Really great technical achievement by Spacex last night. It was pretty impressive that they managed to achieve all the mission objectives. I wonder why they were able to forego the barge landing and go for a full return to launch site landing. I know this vehicle was a bit more powerful than previous Falcon 9's, so that might be it. I haven't found much more detail about that.
With regard to the re-usability (I'm sure Spacex wouldn't be going after this method if it wasn't economical to do so) I wonder what the comparison is in cost between re-qualifying used hardware and building new hardware? You don't just dust it off and fill 'er up. The space shuttle was "re usable" and went through unbelievable refurbishment between flights, including replacement of many components, disassembly of major systems, inspections, re-qual, etc. A first stage booster is a much simpler machine than the shuttle, however.