K here's my final argument before the (not so) inevitable close.
You know that area has alot of strong enemies? Have you actually bothered looking at their exp? Or do you just hear that "Skeles are the fastest?" For me, the risk assessment of braving something that does 3k damage is not worth it (especially if as you say there is a cooldown period). Yes, you were right, ppl had trouble training when Skeles and such didn't exist, but you're overlooking an important detail. That was also before Ultimates. If like you say, they define the class wholly, there are still always two models, DPH and DPS. In terms of this attack, this works more defensively than offensively, that is, if you can't 1hko the enemies, you pick enemies that allow you more than 2hits. This means you either mass a whole bunch of himes (you'd still have two concerns, their spawn while you cooldown, and the possibility of that Tengu boss), or pick some of the creatures nearby that are close to the area but not as offensively strong as Skeles. Hmmm, Jr. Newties are nearby...
Jr. Newtie Level: 105 HP/MP: 68,000/200 EXP: 3,800
Magic Atk: 550
About 1.9k damage (I've tested this at level 80)
Skelosaurus Level: 113 HP/MP: 85,000/250 EXP: 4,750 Mesos: ? KB: 5,000
Magic Atk: 670
Roughly 3440 damage
This means, I CAN take 2hit damage, in theory anyway. The way these enemies are set up is also pretty weird, as you can be in attack range of two of them, or none of them, since they are nested So let's see, 3/4 exp (more actually, but let's not be too nitpicky), for half damage, and kill time is 6/8. Yea, I know I still have to watch out for Nest Golems, but they have very interesting stats.
Nest Golem Level: 110 HP/MP: 80,000/240 EXP: 8,050 Mesos: ? KB: 5,000
Magic Atk: 650
Roughly 2880-3k damage
My sources
http://www.youtube.com/watch?v=uBAIaZGqQvs (for Newties)
http://www.youtube.com/watch?v=6Lay8l7C78s (Skele, Nest Golem map)
Hmmm, slightly lower damage (still dangerous), but I gain two for the price of one Skele (unless that's a typo), for about 5k less HP on their part. Plus, the area seems segmented by level. Meaning while I fight Nest Golems with genesis all the Skeles above get caught in the crossfire. True, it will take longer, since Holy isn't in the most effective list for Nests. But, down below there are plenty of places to rest (ladders and such) while I recover from MP drain or wait for enough time to heal. And, the Newties don't care if I heal.
Besides, as I've told you before (I think), just cause I typically don't use MG doesn't mean I don't have it fully MAXED. I could conceivably go there with MG on and last for long enough to Genesis 2 or however times many it takes. With higher hp, MP loss is less of a drain on either my hp or mp. This definitely beats the last minute pot, because I only have to use when I'm close to running out on MP. My MP is high enough for that kinda thing, I suppose. But why put myself through that trouble is there are comparable enemies for slightly less risk?
You know, I could also simply summon Bahamut, and have him do all my major damage. No lag, no cooldown, no skele problem. It would be conceivably much slower though. Ugh, probably not.
Btw, just for giggles, I looked up Hime. It wouldn't be unthinkable to do this until 200, and just switch to Genesis.
Dreamy Ghost Level: 100 HP/MP: 68,000/350 EXP: 3,200 Mesos: 697-1020 KB: 300
About the same as Newties
(weak to Holy)
So why would you up the challenge twofold to train on something that gives only 1/4 more exp?