Well...it's certainly no secret that SuperdAmn is a huge success. It adds much needed functionality to dAMN...and helps one [nearly] forget that we're stuck within the much more limited constraints (vs that or IRC)of dAmn.
I think the most notable, and used feature as it's been my experience is the "Emotecloud" allowing emoticon artists far and wide to produce and have there artwork used in the chat setting.
The preferences panel, and all the functionality that comes with it such as away system, ignore, color styles etc. are very welcomed features.
SuperdAmn really goes a long way into making something that really was quite the impersonal uncustomizable experience just a little bit more individualized and pleasurable.