True some of the information is replicated on the DIC, but it updates quicker than the DIC and it gives you access to more information at once. I also like the trip features of the SGII vs. the DIC, it can show you stats from each fill up, each day, and each trip (every time the vehicle is started). Other items it can display are interesting in troubleshooting, performance mods, or hypermiling. Like air intake temperature, timing advance, engine load, coolant temperature, DFCO engaged, error codes, and throttle position.
I did not buy the SGII for the Nox. I had it on a 06 RSX that had absolutely nothing in the way of a DIC. I have got so used to driving with it I moved it over to the Nox when I sold the RSX.