ZiPhone better. There is an option for deactivating Bootloader downgrading for those wishing to blast ZiPhone just because of the downgrades. Just be sure to check and do your homework before doing anything.
iPlus can end with BL 3.9 FB which can later turn to Bootloader 3.8, which you don't want. So far BL 3.8 is report wrong IMEI and ICCID and other stuff.