The way the Materia system is now, Items are severely limited in how they can develop. Let's look at the Militia Tights HQ as an example.

Militia Tights HQ: +14Vit +14Intel/Mind +23Crit +13Spell Speed
With the current system, the only practical attribute available to enhance is Piety and the only property to enhance is Determination. If you try to enhance the attributes that are already affixed to the gear i.e. vit intel mnd etc. the Materia won't work. This system was put in place to restrict how powerful equipment can become. This makes sense but it seems too restricted.

If Materia was changed to allow the Initial slots to be used for any offensive, physical or mental properties (accuracy, crit rate, skill speed, spell speed etc). without restriction while allowing advanced melding to increase the attributes (str dex vit etc) I think materia would become more interesting and maintain balance.

Any thoughts?