Some of them overlap with QSurround (e.g. Downmix) plugins. Others are useful depending on what type the recording is. The DigiOn noise reduction, Sonnox and WAVES (total 8) parts of SSMS are the most important. They can transform analogue data or even newly recorded sound into professional quality audio files. Therefore, getting past SSMS software to work on modern hardware is quite important. If I were to choose between Sound Organizer 2 and SSMS Recorder Edition for my ICD series recorders, I’d definitely choose SSMSRE to actually edit the audio. SO2 does the converting/ or Audition if you have it, and Audacity can be used when you need it. Personally, SSMS’s design appeals to me over Audacity anyway.