The brickbug is caused by performing a factory reset. Installing some custom ROMs or restoring nandroid backups performs a factory reset and thus may also brick the device. It should be said the probability of this happening is pretty low but the problem is real and you should be careful. There are quite a few workarounds now to make things pretty safe, such as modified kernels and recoveries.
If you want to move from a rooted stock firmware to a newer stock firmware and maintain root then mobile odin with 'everroot' ticked is the best option. This should be pretty safe as no factory reset is performed.
If you want to move from a rooted stock firmware to a newer stock firmware and maintain root then mobile odin with 'everroot' ticked is the best option. This should be pretty safe as no factory reset is performed.