I will agree that SFK is much better than RFC or DM. For one thing, the mobs in RFC have that annoying knockdown/stun that can hit a level 70+ player repeatedly, which makes it take forever to round them up. Second, the mobs in SFK do not run in fear, which means you don't lose any time chasing down low-health runners (although a level 70+ can probably nuke them down before they even realize that they're low enough to run). It's also a very short zone with a high mob density.

Argh, now I want to level a new team...