How difficult is it to run dungeons as classes, not jobs?

[Mysteltain]

There is a cap on materia. Pieces can only be maxed out via materia to an extent. You'll get a message when you try to afix materia that would go over the cap warning you.

I'm not saying it's impossible. But just that materia can only do so much. And considering that at that level there aren't many materia slots on each piece to work with, you certainly wouldn't be able to compensate for all the stats you'd be losing without the Crystal.

Well, that's why I said clever; I know about the materia stat limits. What I'm given to understand is that you're only capped on the stats presented by the weapon. So if an axe had, say, +4 VIT, +3 DET, +3 Parry, what's stopping you from adding STR materia to it? And then if you have earrings that don't have a VIT stat, what's stopping you from stacking VIT materia? Mind you, I haven't tested this, nor have I messed around with materia all that much, but it's an interesting idea.

Also, I think you're forgetting about overmelding. Up to 5 materia can be attached, although you'd have to be lucky as hell to do so on more than one piece.