How Much Gravity?
Stations with different periods of rotation or different levels as in Kalpana One with her nested cylinder approach will provide a variety of different gravities available to live work and play while living on a space station. Just how will we use these varying gravities?
High g
Heavier than normal Earth gravity of 1g can be established by adding levels below or further out from the center of rotation than the 1g normal gravity of the main living level. Experiments in the field of metal casting, forging extra dense metals and new alloys will be created. Imagine regolith molded into an ultra-dense ceramic Stronger than steel at a tenth the cost.
Another advantage of higher g-force may be physical fitness, here people could get an extra heavy workout to prepare for sporting events without the more extreme g levels to work metals.
The cost of adding so much extra mass to create this sort of high-g area will be prohibitive in early space settlements. They would be more suited to experimental barbell stations at first.
Low g
Lower than normal gravity levels are much more realistic and useful in early space settlements. While it would be 1g on the living area of a rotating space colony. Inside a rotating cylinder as one moves closer to the center of rotation gravity decreases. Areas of lower gravity can be used for storage, Low g manufacturing.
Building satellites in space will be a major industry in space. Harvesting raw materials for construction from the moon and asteroids will save billions in costs over earth-bound manufacturing. Space settlements will always be in demand for the growing population of Earth.
Earth Normal 1g
All the people building satellites will need a place to live so settlements orbiting near or better yet a part of a working space arcology. Commuting to Earth from the asteroid belt or the moon is just not practical.
Prolonged living without gravity is detrimental to the human body. I think no one will want to be the first person to raise a baby in a low-g environment. So, for the time being we will need some sort of artificial gravity if we are to become a true spacefaring race.