nex-7 or nex-6 which is ultimately better?

I don't think saying the 6 is better is accurate at all.  It can be better depending on your needs - if you use a lot of wide angle lenses and adapted lenses or if you think you will benefit from wifi and apps like timelapse, etc then the 6 may be a better fit.  If you need the very best resolution, build quality and controls the NEX 7 might be the best option.