A fellow who used to be here on TPF messaged me, asking about the Tamron 24-70 versus the Canon 24-70mm 2.8...I went to
Full-size sample photos from thousands of lenses and cameras :: Pixel Peeper and looked through a BUNCH of sample images made by the Canon and the Tamron....where the Tamron loses is its aggressive bokeh, and its unfortunate "onion-ring" bokeh signature, which ruins its images for m any types of photos...
If you look, owners of the Tammy seem reluctant to post sample photos of it in obvious "bokeh ball" type situations, which are many and legion in the real world, but if you go through the samples, you'll find some photos.