I'm going to try this this weekend - I'm not talking about the "upstairs" of Siren's. Most folks forget that Siren's is actually a decent sized zone, once you swim down the well. Thats where the mobs are light blue (old blue cons, so still okay xp), and sirens, not the horses.
I've hunted up top, and at 70, your right, its weak. I still do it on occassion for tribute items, and deepwater Ink for a guildie shaman though.