Aren't a lot of people here missing the point, that a Dyson Sphere might be the only thing you can actually build in some systems?
Arguing about how a mining station is more efficient is all nice, but for the 400 energy that would be about 100 average star systems to fill with mining stations. So often the choice seems to be "Do I just waste this mineral surplus and leave some star systems unused or do I spend the minerals on a Dyson Sphere and generate 400 energy with that otherwise useless star?"
Of course, being able to build just one structure at a time is not so nice as you will still not be able to use all systems.
Arguing about how a mining station is more efficient is all nice, but for the 400 energy that would be about 100 average star systems to fill with mining stations. So often the choice seems to be "Do I just waste this mineral surplus and leave some star systems unused or do I spend the minerals on a Dyson Sphere and generate 400 energy with that otherwise useless star?"
Of course, being able to build just one structure at a time is not so nice as you will still not be able to use all systems.