The Duo (v1) and Duo v2, and also the NV+ (v1) and v2 are very different products.
The NetGear v1 units are e.g. RND2000-100 and RND4000-100. Also Infrant NV+ units are v1 units.
Note that some v1 units are called e.g. RND2000 v2 which is confusing.
The v1 runs RAIDiator 4.1.x or earlier. The v2 runs RAIDiator 5 firmware.
The v1 units uses the Infrant IT3107 storage processor whereas the v2 uses a Marvell ARM CPU.
The hardware and firmware are quite different. Articles here for the v1 units do not apply to the v2.