I have just picked up an XL with FW8.4 (I believe). The first thing I did was make a NAND backup with gateway, and downgraded to 4.5. Now it might be my imagination, but prior to downgrading, the 3DS seemed to power on almost instantly, after downgrade it can take almost 20 seconds. What I'm planning on doing (If possible) is either upgrading with Smash bros, or restoring the NAND backup, and launching the Gateway exploit with the browser instead of the profile glitch. Does this sound reasonable? Any precautions I should take?