Not the best standard zoom, but quite close and likely the best value. The only other competitor I see for this lens is the Nikon 24-70mm as no other standard zoom is stabilised (for DSLR's). For much less than Canon's equivalent, you get a stabilised standard zoom that is practically 90% as good. The Tamron softens a touch towards the telephoto end, but it's far from unusable. I had no issues with the focus on an EOS R and 6D Mark II: it was quite accurate and snappy in both applications even in low light. There are some chromatic aberration issues wide open and more vignetting at the wider end, but that's standard across these types of lenses. The build quality is quite rugged, and the weather sealing assures me it will last quite a long time, although I'm not one to shoot in harrowing situations. Because of this and the 45mm lens, I have complete faith in Tamron's SP line delivering fantastic results and would absolutely recommend this lens.