South is level 64-67 critters(lv 59 rec to hit)
East is mid 70s to upper 70's (Hiya (66 Sorc) and I could take them on, but we were missing alot) you really need mid to upper 60's to hit effectively in east area. This is the area that all the mid 60's power fellows are racking up huge xp. 600 mill on mana in an hour are the kind of numbers Ive heard.
West is upper 50's to low 60's critters. Martel (52ish Sorc) and Taurolyon (51 healer), you asked me last night what level HoD is, and I forgot there was an area with upper 50's low 60's. This area would be a good hunting, and probably good solo area for a mid 50's toon.
Note: The HoD portal is only accessable by level 55+