I logged on after work yesterday thinking I'd screw around crafting a bit and then play some FFII. But when I logged on Tom said it was Mithra week in Gusgen Mines and I should head down and 'help' him. I put help in quotes there because he'd already gotten one piece himself so clearly he can solo the place. White mages are pretty terrible at helping to fight things. Awesome in keeping a group alive to be sure, but not great in a team of two. Fortunately I got thief up to level 15 on the weekend and thief gets an iconic ability at level 15: Treasure Hunter. Unfortunately it isn't clear exactly what TH does but it definitely increases the drop rates of items. Like, say, chest keys. So even if having me along wasn't really speeding things up in a mobs per hour standpoint (though I am sure it was since every 2 fights I get to do a weapon skill which is about as good as one of Tom's autoattacks) it should definitely have sped things up in terms of keys (and other loot) per hour. We got 3 Escape scrolls to drop, for example, and they're worth ~18k each.
It also turned out the mobs we were killing were xp chainable for me, though the amount per mob was lowered from having a higher level person around. I still ended up gaining a level essentially for free since we were doing other stuff primarily.
We ran right down to the wire, finishing with about 26 minutes before the week ended, but we did manage to end up with 7 keys. With the 1 Tom got before I got home from voting yesterday we had enough for a full set of gear each. I can't speak to how much better level 30ish gear makes Tom but it definitely makes my level 32 WHM a lot better. 20% more max mp and a bunch of extra hp and stats! I have high hopes for smashing some MMM mazes tonight.