Oh, it's really, really easy to use. My VSX-23 does have some more manual options that involve multiple positions (I just can't avoid saying these things now

), but I just run the full auto routine and then adjust my speakers to "small" because it always sets them to "large." The full auto routine involves (a) hooking up the included microphone, (b) placing the microphone, and (c) starting the routine. It couldn't be easier. I think the results are a definite improvement over not using it. I still remember getting my first receiver with auto calibration (it was also a Pioneer in 2005) and being blown away by how much better my system sounded.
Ed at SVS recommends setting the volume on the sub to the highest level possible and setting the output on the receiver lower as needed. He says that the amp performs better that way. I had to turn the volume on the sub down a bit because otherwise the output was too high for MCAAC to get all speaker levels set evenly. No complaints there

, as it meant that the sub had plenty of oomph for my room. I only had to set it down to about -5 dB to get the routine to run, so not bad at all.
Thanks, and that's really nice of you to say!