Yeah the 3K price increase is small but the amount of road trip I do, I think the 90 is sufficient. Again like other have said, it is to make up for the lack of free supercharging which can be quite a bit if one does a lot of road tripping through out the life of the car.
The only benefit I can see is from wk057 analysis, the 100KWh seems to be an actual 100KWh battery with 96KWh usable. The 90KWh battery is actually a 86KWh with 81KWh usable. So one is really going up 15KWh usable for $3K price increase. At this point, i see no point in getting the 90D over the 100D if both have 400KWh free supercharging per year.