mix engineer here - 2 X MIO2882
i have the Transformer character parked on all 16 D/A after trying them all out. the cumulative difference is more obvious, and it's easy to insert/remove characters on all D/As at once, just select them all at once in the mixer. sometimes i throw the SoftSat on a track that i want to stand out in a different way... FYI SoftSat is the only character that adds a dB or two to the signal.
here's a link to a thread where we compared characters with SpectraFoo:
http://www.gearslutz.com/board/3843143-post699.html