From Joseph Telushkin’s biography, Rebbe: The Life and Teachings of Menachem M. Schneerson, the Most Influential Rabbi in Modern History:
My wife, Dvorah, often commented that whenever I spent the day researching at 770 Eastern Parkway, the generic address for the Chabad movement’s Brooklyn headquarters, I came home in an uplifted, invigorated mood. That is because Lubavitchers as a group are upbeat, a result in large part of the influence exerted upon them by the Rebbe and his teachings, even now, almost 20 years since his death. If one can make a generalization about so large a group of people as Lubavitcher Chasidim, one generalization I feel comfortable in making is that Lubavitchers exude a warm calm and optimism, they avoid negative language, and the mood they convey is contagious. I am a happier and more spiritual person as a result of writing this book…
* Failed Messiah has a post on Chabad mobile succah.