Michel has right Dyna Soar was not perfect but was improvable for sure....
Despite it was claimed as "operational vehicle", the Dyna Soar was intended by since as research aircraft (that's why it was still known as X 20).
In this optic there's no surprise to have only one pilot, even in space, considering that X 20 was intended as an upgrade respect the outstanding X 15.
And there where plans to put an X15B already in orbit (ok I don't want to go OT, and I will open a specific thread about X15B soon).
I suppose that if Dyna Soar would be realized it could (potentially) be one of the most notably machine ever flown, especially considering the time of its design (the end of '50s).
Anyway even if it was never realized, the Dyna Soar left a deep impression in all the people who are interested in Aviation & Space, the proof is the fact that we still discussing about it today (in several dedicated Forums the topics about X20 Dyna Soar are countless...).