Is the highest Paradise (Firdaws al-A'la) the highest rank in Paradise for humans, or is the rank of the truthful (Siddiqin) higher than it? And is the bliss of Paradise uniform, or does it vary among those who enter it?

Al-Firdaws is the highest level of Paradise absolutely for all dwellers of Paradise, from all classes and eras. It means the best and most central part of Paradise; it is the very core of Paradise. There is nothing higher than it except the rank of Al-Wasilah, which is exclusive to the Prophet, peace and blessings be upon him, and it is the highest part of Al-Firdaws. Al-Firdaws is the highest part of Paradise, and within it are levels, the highest of which is Al-Wasilah.