GSO is very high orbit (22K miles) and therefor has much higher latency. The lower orbit (100-1K miles) constellations are lower bandwidth because of the high angular speed of travel removes the ability to do directional (high powered) transmissions.
Incorrect. The LEO constellations use phased arrays (or similar) and are able to slew at whatever angular rate you could want as they are electronically steered. Both for the terminals and for the satellite side. Iridium has used phases arrays in its LEO constellation for decades now, and the newer constellations like OneWeb and Starlink use phases arrays on the terminal side as well.