It’s the best place for Recruits that I can also autoplay at a reasonable speed, so I can run the number of Flasks I usually go through during AR.
6-9 takes considerably longer (I timed several runs in each), so it’s not worth the 6% increase. And I couldn’t reliably autoplay 15-9.
I do use Loot Tickets on 15-9 (or 6-9, to finish off WE, depending on my flags).
I’m farming Recruits because I’ve been running TC1 and TC2 nonstop for months, so the only thing I need to keep them going is Recruits, while I burn through my backlog of Practice Swords.
I’m down to 2,206 of them, from 10,867 on January 31, shortly before I started running TC1 nonstop.