You can exploit 1.0.0-0X with Cubic Ninja and you can dump the OTP directly in it.
But now there are easier ways to do things like dumping the Nand and OTP in with ntrboot. You can"t do much in 1.0.0-0X by the way.
1.1.0-1X added a "Limited time 3D Video" that was removed in 2.0.0-2X, if you got it somehow (from example before old titles were removed from CDN) you can actually downgrade just that tile to get that 3D Video in higher firmwares.