The Vivo V3 Max is a better phone as it gives a better processor than the Samsung Galaxy J7.
Processor: The Vivo V3 Max comes with the Qualcomm Snapdragon 652 MSM8976 processor whereas the Samsung Galaxy J7 comes with the Samsung Exynos 7 Octa 7580 processor.
Camera: The Vivo V3 Max has a camera of 13 MP with F2.2 aperture whereas the Samsung Galaxy J7 has a camera of 13 MP with F1.9 aperture. The Samsung Galaxy J7 is better with camera quality.
Check Full Comparison Vivo V3 Max vs Samsung Galaxy J7
I couldn't find any major differences between them. On8 has better display than J7 2016 and J7 2016 has better processor than On8. I'm using J7 2016. Its performance is very good. I have seen On8 also. J7 2016 is slightly faster than On8 and has better graphics too. You can go through this comparison too. Compare. I'm attaching a video which I just found on YouTube. This might help you in picking a best one.