I just used 4 elemental shaman to boost one rested level 70 through old kingdom. It took about 4 hours... kinda slow but at least I could then put her in the 71-80 av bracket. Not really worried about boosting 71-80 anymore, just trying to figure out a good way to get my new toons from 70-71... the experience for a level 70 in AV is pretty bad