Both the real DNA and it's clone can not produce a voltage under that of the battery while the SX350 will go down to 1.5.
The Chinese clones of the DNA30 have had problems with the accuracy with which they read resistance.
The Chinese clone is a copy of another board, it uses different components and layout and programming while the SX350 is an original board.
The DNA and it's clone have a bug, if you ask for a power the chip can not deliver it flashes the resistance, only while you fire it, and gives you more wattage.
The SX350 is newer and I am sure cheaper mods will be coming.
There is an update for the firmware on the SX350 that will let it go to 50 watts, 66% more than the DNA.
The user interface is nicer, the saved power settings let you change from 5 watts to 50 watts in one step. The SX350 can take input from the accelerometer. If you prefer it can use buttons, like the DNA.