General Leveling question need some advice

Hello,

Here is my group

80 Prot Paly Adimas
2 62 Ele Shaman Utook and Ytook
1 71 Ele Shaman Otook
1 70 Priest

I was wondering if it would be faster to level my 2 62 shamans to 70 questing or boosting in UB and SteamVaults

Just wondering what people thought, I have been boosting in UB and SV but is getting old but want to be as fast as i can leveling to 68 so I can hit WoTLK instances.

Thanks in advanced

Have a great day 8o

Adimas

Quest boost them through Zangarmarsh a bit of terrokar then on through Nagrand.
You'll burn through the quests.