McMurdo vs Ocean Signal MOB AIS comparison?

[Dr. Sea]

Does anyone have personal experience with the Mcmurdo Smartfind S20 Srs AIS Mob Beacon vs. the Ocean Signal Rescueme Personal AIS Beacon? They both will send out an AIS signal so that any nearby boat (presumably your own) will be able to find you in the water and they both have a built-in strobe light. From the Ocean Signal's advertising, "MOB1, unlike any other personal AIS Beacon, also provides a second way to assure your rescue, using DSC-equipped VHF radios of any vessels within line-of-sight range. You can manually send an All Ships DSC distress call by pushing a button on the device, in case your own vessel is unable to hear your transmission or respond." That seems to make it superior to the McMurdo. Does anyone know of a reason not to prefer the Ocean Signal device?