I own ARC and have enjoyed using it over the years but the Sonarworks bundle is making me consider replacing ARC.
It Calibrates your room and speakers (like ARC), it also has headphone calibration (ARC doe not), and for extra $, has a new software that will route your internet audio through the Sonarworks calibration software (ARC does not). The price for the speaker/headphone/microphone bundle is decent, and it includes an individually calibrated microphone.
I will get the Sonarworks demo and try it myself, but in the meantime...
Anyone prefer Arc over Sonarworks for any technical reasons?
Do they both calibrate your speakers about the same, or do you prefer the results of one over the other?