"I'd buy the Canon 10 - 22 mm lens in an instant if I had a Canon digital camera. The Canon 10 - 22 mm is better than any of these four lenses, including the Nikon.
What makes the Canon so superior is its vanishing low distortion. What little distortion the Canon has is completely fixable in PhotoShop CS2. The Canon also has a wider zoom ratio than any of the Nikon, Tamron, Sigma or Tokina lenses.
If you own Canon and want the best just get the Canon lens. it's not much more expensive than the Tamron, Tokina or Sigma lenses and costs less than the Nikon. "
Yes, but IMHO, the Tokina 12-24mm is priced too close to the Canon 10-22mm.. UNless compared to the Nikon 12-24mm, then the Tokina makes much better $en$e..