I used both (in parallel, for over a year), and I can confirm that the 3GB 1060 is significanlty more powerful than a a 4GB 1050ti. They are in a different league, no matter the tweaking, and the +1GB VRAM didn't help the 1050ti much in my case. The 3GB version of the 1060 was always a compromise, but I found that I could live with that, as in most cases, it wasn't powerful enough for the VRAM munching options at 1080p anyway (at least for the games I have played), and it could deliver high settings consistently for 1080p/60 accross a number of games. I have moved on eventually to a GTX 1070 (which I still own, and it seems I will own for a while...), but I quite liked the 1060 3GB for the years I was using it (1440p would be most probably a different story)