Jgaropel ill share my experience and why I bought a Sigma 17-50 instead of the 17-70 which was also my first choice before and why im selling it now. My experience with the lens, its really very sharp compared to my other lenses I was really satisfied with it but I have to let go because carrying it around (DSLR) camera and lens especially on vacation wasnt fun anymore, I found it to heavy. Reason i bought the 17-50 instead of the 17-70 is because it had great reviews compared to the 17-70 and lastly is when I searched for budget zoom lenses for Nikon, I found this website dxomark.com which is a very trusted website for rating lenses and even Tony Northrup relies on dxo. Notice the chart on the link, sharpness of the 17-50 is 14 while the 17-70 got only 9.
https://www.dxomark.com/Reviews/Best...-for-the-D3300. This was the main reason why i bought the 17-50 instead of the 17-70 and I hope you will buy mine 12k only still like new.
https://www.istorya.net/forums/photo...-18-200-a.html