Just did 8 runs through the new "Hard" level of the scrapyard. Had great success and am definitely glad we finally have access to this much quicker method of leveling. Here are some of the highlights from today:
When sparring with a Metal King Slime, you get 50,000 experience (equivalent to five Liquid Metal Slimes). That last run I show there then is effectively like getting 16 Liquid Metal Slimes from a single run-through.
As an added perk, the encounter rate of regular metal slimes is waaaay down. It was always annoying to do a run of Scrapyard: Medium and get mostly Metal Slimes.
Oh, and another observation was that there are objectives for this quest with rewards, 50,000 Gold for not dying and a Metal King Slime if you recruit a Metal Slime Knight (which I did on my fourth run).
Happy grinding everyone!