One thing I have noticed even with Carbuncle Mitts is that Summoner is the only pet job that has such a bad hindrance to deal with, and that is Perpetuation cost.
1) "Even with carbuncle mitts?" I don't even carry carby mitts anymore. You don't need them AT ALL for free carbuncle. As it is, it's easy to negate the entire perp cost of any avatar.

2) "Summoner is the only pet job that has such a bad hindrance to deal with, and that is Perpetuation cost." Overload and Burden are as bad if not a worse hinderance than perp cost, which is really very trivial. Summoner's real problem is blood pact timers.

If you think perp cost is a serious issue for summoner, than you probably need to upgrade your gear.

The irony is that carbuncle is bad on them, even though you expect undead to be weak to light damage. I think the highest I've seen is about 500 damage, and that is still a JA higher than level 75.
It seems to be a rule of this game that light element cannot be powerful. Holy mist is only BARELY better than meteorite.