Actually, I found it to be quite opposite. When I was leveling my Shaman, it was much easier to level as Enhancement rather than Elemental for me. I was burning through mobs left and right without much trouble at all. I didn't even start trying Resto or Elemental until I hit 79-80 (back in WotLK days).
You shouldn't have any problem leveling as Enhancement.
Jornam 45 Jedi Sage - Sith Wyrm
85 Blood Tank / Frost DPS DK Kriscoe
85 Resto / Elemental Shaman Handalf