Auberon is better in general. It becomes pale kaiser, which is a fantastic GS. Yes, it becomes outclassed, but it is a very easy to obtain, extremely flexible sword. Generally when it comes to great sword, count one point of raw for three points of element.
Yes, auberon has 0 fire unless awakened, but many monsters take 0 elemental damage unless it's their weakness. Also, the glinsword is outclassed in every way by the gleamsword.