Nothing special about it, its just a mode setting that provides enhanced recovery like FA mode on the F75. Look, I own an AT Pro (and an ATX for that matter) so this is not a Whites vs. Garrett (vs. FTP vs. Minelab vs. XP) thing for me (I own or have owned them all), and the only reason I am looking at the MXS is to see if it is better physically balanced than the ATP in a watertight package. I am personally willing to take some variation in performance vs. the ATP if it delivers on that front. It works, for me, out of the box from am electronics standpoint, so far, but still testing it to see if I can swing it for long durations and to see if it falls down under specific situations. If the firmware makes it even better, then gravy. Jury is still out for me until I put it through its paces. Then I will decide to keep it or send it in for the fix. I am having trouble understanding the brand vs brand/model vs model posturing that is dominating the discussion of this model. To me, it is somewhat irrelevant. No one is forcing anyone to give up their favorite machine to go buy an MXS. And just because someone does go and get an MXS, not sure why they have to be told, well you don't have to do that with my favorite detector, so Whites blew it. It makes no sense to me.