Acceptable Motion
In designing seasteads we need to understand what amount of motion is acceptable.
The basic problem is that your brain is used to being able to tell what vertical is by looking at buildings and things, but on a ship it is not so simple. The conflict between visual cues, your inner ear, and the motion your body feels causes the trouble.
There have been studies working out formulas for what amount of motion causes sea sickness.
In general it seems that after a few hours to a few days people develop "sea legs" and are adapted. If tourists are coming for 1 week visits a few days to adapt takes away a lot of the fun. If a family is moving onto a seastead for good, a few days to adapt is no big deal. Minimizing motion is more important for short term tourism.
Many people travel on small boats with lots of motion and are fine after an adjustment period.
Stability of Competition
For comparison here is a very stable $4 million yacht. It was designed by the Dashews and is called "Wind Horse". There are many videos on youtube. It has very large active stabilizers. If we can be this stable then we are doing well.