This Mercury Retrograde is more intense because it's within the influence of the two eclipses this month that are:
September 13 - Solar Eclipse in Virgo
& September 27 - Lunar Eclipse in Aries.
Mercury Retrograde is the time to be more thorough with all communication and travel. It's easy to experience error. The 3 week cycle is great for reorganizing and revising but not for major new beginnings.