Hopefully this lens matches the IQ of Tamron's 17-50. It seems to look a little nicer than the 17-50
I *very much doubt* that'll happen, since it's an UWA with a fairly comprehensive FL range. If they gimped the FL to something like 10-15 (similar to what Tokina did with their 11-16), then that's plausible. Otherwise I'm expecting this new Tammy to have pretty good center sharpness (comparable to a 17-50), but the corners won't be so pleasing on the eye.