Just for clarity, if you downgrade to 9.2 via any of the current hack methods, then you can restore any previous sysnand backup file you made via the gateway menu (gateway card NOT required). You need to copy the sysnand backup file to the root of your sd card and make sure it is called NAND.BIN. Then launch the gateway menu from your 3ds browser via url go.gateway-3ds.com (edit: make sure you copy launcher.dat to the root of your sd card first, available from gateway
downloads in the gateway ultra .zip file), select the "downgrade" icon (last icon on rhs) by holding down "up" on the d-pad while pressing A. You'll then have the option to press START to do the sysnand flash (or b to cancel). Takes a couple of minutes, make sure your battery is well charged.
For people who are not bricked and have a sysnand backup file - there is currently no need for a hardmod to restore your sysnand (until nintendo update beyond 10.3 firmware)