since this thread has migrated towards lenses, I have a comment and also require some feedback.
First, Sanjay, those Tokina lenses are nice. I miss my 12-24. That thing was friggin sharp!
Now, for some feedback...I moved to a full frame and the price jump caused me to sell my super wide and I have yet to replace it. My 24-70 is now wide (moving from 1.6x crop) but in a few situations, I desire wider. Like a 17-35. My initial thought was to sell the 24-70, replace with L glass, and then buy a 17-35, maybe third party, most likely canon. My dilemma is this, my sigma 24-70f2.8 ex dg makes great images. Not as good as my L glass, but very nice nonetheless. And the price jump up will probably leave my wallet screaming if I then buy a 17-35. So, my thoughts are this, buy a 17-35L, keep my 24-70 and eventually swap that out. I feel sorta naked without a super wide. Since I primarily do landscapes, I kinda *need* this lens. Thoughts?