I didn't use the vintage lenses all that much, autofocus and zoom is just much more convenient. Also on the web 4k is pretty much the max viewable resolution. Camera lenses are designed for the sensor resolution which is typically 2-4x that amount, so lens quality almost doesn't matter for pictures viewed on the web.

I chose the GX7 because it's really small and light with decent image quality. If I were getting started now I'd be taking a serious look at the sony A7 M1.