I've been getting alts to 70 with my shaman team of 4. Running them through chain Instances actually is not a bad way a leveling up. SL and SH gave about 1500-1650 exp per kill on the 70's. I got a 5th shaman to 70 this week and doing so I got two levels on my other 4 ( now 72 ) I plan only to level them when they have rested. Leveling one to 80 ( my warlock ) was bad enough with collection quests, 5x would just turn me off to wow completely.