[quote name='KingBroly']I know that much, but Traps drop easier after Mission 51. However the enemy that drops them becomes a lot tougher.
I've done the Faultwarrens twice so far, but I think I'll need to do them at least 3-4 more times[/QUOTE]
What activates the transition of Adamantoises to Long Guis is the completion of the Marks all in a circle in the northeast Steppe. It has nothing to do with the Faultwarrens. Completeing the Warrens 7 times and killing Mark 51 (Attacus) allows you to do Mark 64 (Vercing.). The Gold Watch is utterly useless if you're using maxed weapons and such. The extra time if gives you is literally a couple of seconds (less than 10).
Long Guis are a pain to farm, but the good thing is there will always be the Adamantoise in Eden you can farm for Ingots.
Long Gui's drop rate for Traps is 5%, while that of the Adamantoise is 1%. Combine that with Connoisseur's Catalog, and you have a much higher chance to get traps if you farm Long Guis. The kill time for a Long Gui is roughly 2x that of a Adamantoise in the best gear though.
Also, you will eventually need to farm 6 Dark Matters from Shao Long Gui. Believe it or not, the smaller Shao Long Guis are harder than the Long Guis and will absolutely wreck your party if you're not careful. You sort of need to be extremely offensive and have amazing gear or you're looking at 8+ minute fights. I was using a defensive, more careful strat. in the beginning and became extremely frustrated by them. But, messing around I ended up getting my kill times down to 2 minutes, which isn't bad at all.
EDIT: My barebones FAQ for Upgrading and such is on GFAQs now,
http://www.gamefaqs.com/console/ps3/file/928790/59358. Format and aesthetics are terrible, but I'll change those later. If there's any useful information that any of you want to see in there, let me know. I need some sort of feedback.