I think it's really impressive how SpaceX continues to iterate on the engine and rocket designs. This is the third major revision of the Falcon 9 engine since 2010, each time increasing the thrust and payload to orbit significantly even while operating a commercial launch service. I feel that this kind of willingness to continuously improve and push the envelope is what really sets SpaceX apart from the incumbents. Speed of iteration beats quality of iteration and all that.

It's quite interesting that their biggest competitor ULA is having to rely on tiny Blue Origin to develop a replacement for the Russian RD-180 that ULA uses on their big money maker Atlas V.