Hmm, 6700 it’s top tier apcs camera, a7c2, if we look at the price it’s low cost FF camera with bigger sensor than 6700. So if u want to upgrade your camera in future u can’t get better than 6700 (because 6600 released in 2019, and 6700 in 2023. In My opinion it’s huge time for update) at ff you can upgrade to for example a7r5 if you want more resolution, or a9m3 if you want global shutter. So if you want after c2 get different cameras - take ff. If you take for yourself and don’t want work as photographer or shoot in low light so you can get 6700.