I had a 4GB microSD card lying around, so I used it for the internal FW card. I saw that the OS used around 1GB of space on the original card the RG350 shipped with, so I said well, how much more space would the CFW use? I installed the 1.7 on this 4GB card and it works just fine.
My question is, is there any reason why I shouldn't keep this 4GB card for the internal slot? Should I use a bigger one? I searched around and I haven't found anything about the minimum or recommended size for the internal card. Truth be told, I figured out that some of the game ports have to have the game files copied to the internal card, like Diablo/Devolution, for example, so that may take some space, if you want to play all the ports available.