So what is really different about it compared to the G700?
500nm more range, different window layout (is it of composite fuselage construction?).
Web site poorly done for actually learning about the product, range map not functional. Put in Hype category.
(Someone via Wikipedia says it has same wing as G700 but is 10 feet shorter. So it is a replacement for the G650ER, using the wingspan of the G700. (To the extent that the Wikipedia author has understood the products, not perfectly.)