New Tamron 17-50mm F2.8 SP Di II VC same IQ as Canon 17-40 f4L ?

As I tried the double priced 16-35 2.8L II allready I returned to 17-40 f4L temporary.

I wonder if anyone works with the new Tamron 17-50mm F2.8 SP Di II VC on fullframe, does it perform likewise as 17-40 f4L, as any uwa zoom isn't perfect or sharp in the corners, even the L's.
Otherwise maybe the old Canon 20-35 2.8L ?

I don't like to have f4 lenses, it's nice to have the fastest f2.8 for zooms

Tamron 17-50 is very good lens for the price. At f4 and higher I think it can rival any lens in the range. At f2.8 it is a bit soft ( still very good compared to the kit lens ).

Tamron 17-50 is for crop sensor 1.5x (nikon/sony) or 1.6x (Canon) only. Image circle is much smaller so will vignette badly on FF.

To add to the above post: Tamron 17-50mm is designed for crop sensor cameras. You would have a circle of image surrounded by black on a full frame camera.