Not big difference between vivo v5 and vivo v7 plus. But I will share here my experience and differences between vivo v5 and vivo v7 plus,
I noticed there are camera quality of vivo v7 plus is very bad than vivo v5,
I have taken selfie by vivo v7 plus and vivo v5, so I found very good image in vivo v5. While v7 plus having 24 megapixel front camera.
Rest of other features are same as vivo v5.
I have own it, but it is not bad and not good also. Beacause I take less selfie.
If you are looking for selfie phone than I will not recommend.