The major assests of the Maestro are the weight, durability and multi-lingual ability.
The Maestro weighs in at 2.75 pounds with the three hour battery and 3.44 with the 9.5 hour battery and is 2" at its thickest. Yet it has a full size LED screen of 10.4".
The Maestro has a magnesium case with port plugs and is spill resistant.
Other than the size and durability the Maestro is a fairly standard issue AAC device. Bluetooth, WiFi, 2 USB ports, a camera (it does have zoom and pan which most AAC devices don't have, but it is in a weird place and could not be used with any accuracy if the device is mounted), microphone, 3 or 9.5 hours battery life (depending on how much size and weight you are willing to trade off for portability), e-mail, SMS messaging, built in stand, forward facing speakers (if you use the device flat), two built in switch ports - the works, but the same works as most devices. There is no internal CD/DVD drive, which is also now standard on new AAC devices. Also no hot swap batteries or external volume control. (Check the specs.)
Software wise the Maestro runs InterAACt, the same as the rest of the Dynavox version five devices. InterAACt has some nice features especially around quick conversation, but there are some issues with symbol set mixing and inability to "turn off" visual scene displays for those who don't need/can't use them. I assume you could get Gateway, Word Power or another vocabulary set installed on the device.
All in all this is a device I can't wait to look at for student who need something light weight and tough.