The shuttle was amazing. Bleeding edge technology that pushed just about every boundary of what was possible in space. The problem with that? Pushing boundaries is very expensive. Multiple people- from the people at the Planeteary Society, Phil Plait, some JPL people I know for example- believe that the shuttle's high cost is why we have not left low earth orbit in 50 years. A program like the Dyna-Soar or likewise would have been a factor of 10 cheaper leaving more money for things like a moon base, bigger planetary robotic missions etc.
I love the shuttle. I love listening to Shuttle astronauts talk about what it was like to be a shuttle astronaut. But my admiration for the program is cooled by the reality of what it was able to do, its costs and all the compromises that went into the design to get the funding. I saw two landings. One of my big regrets in life is that I never got to see a launch.