I've used Audyssey XT and XT 32, MCACC, and Dirac. I've also used miniDSP as a subwoofer correction and speaker correction. I also have an anti-mode dual core 2.0 which can EQ 1 sub, 2 subs, stereo subs, or stereo speakers.
I like Audyssey, but it does have its limitations. I still have my sights set on Audyssey Pro when I can afford it. MCACC I really only ran the auto cal once for someone else, but it seemed half decent. IIRC, and it was awhile ago, I didn't feel that Dirac was worth the extra money over miniDSP. Dirac easily had the better UI and I believe it had more filters, plus I think you could save as many configurations as your hard drive could hold and would do some other stuff as well. However, the premium cost of the software, plus the need for a high end sound card with inputs and outputs, with dedicated PC for the setup meant it was well beyond what most people could afford and I didn't feel that it blew REW and miniDSP away. I felt the REW autocorrect worked almost as well, that you could get pretty darn good results with it if you took the time to experiment with the parameters a bit. However, with enough cash Dirac could be an extremely interesting solution, especially if they are able to scale up the software to more than 8 channels.
Then there's the antimode. It works pretty well, but the screen is tiny and, again, I'm not sure it works any better than Audyssey subEQ in terms of an auto cal nor do I think the user interface, both the hardware and software, are good enough to make it worth spending almost $800 more than a USB mic, miniDSP 2X4, plug in, and downloading REW.
Just my 2 cents.
