A full discharge-charge cycle is worse than several 30-80% charges. For portable devices with battery life above 5h this is also mostly the case in practice but the shorter the lifespan and the more frequently the device is used, it's the other way around.
For example, a laptop these days often is used plugged in, thus battery stays around 95-99% all the time degrading the battery.
Another example is a smartphone, mostly this is charged up to 100% and recharged after a day's work to 100% again, plugged out and the "cycle" restarts.
For the X3 the situation is different, I am quite sure most users will use it up to a few hours a day and charge it after a few days to a week, not always fully because it takes so long. This is the preferred case for any Li-ion battery.
Charging time has little effect on the dergradation of the battery but the charging time is important for the sort of use the device will see in practice.
It also takes more effort to charge from 90 to 100% than from 70 to 80%.
All rather off-topic.