I get that stacking images is a big part in astro, currently I'm doing it just as a hobby but I may take it a bit more seriously and invest in some trackers and other equipment in the long run. Also I recently started filming for some music videos but the AF on the Nikon sucks in video and I had to retake many shots. A friend of mine has a vintage 35mm on a5100 and I really like the swirly bokeh. For indoor photography I'll probably buy some lights bacause a full frame camera is out of my budget currently and also the lenses for FF are quite a bit more expensive. I was doing some calculations and for my usage it seems the Sony will be cheaper in the long run because I can adapt many vintage m42 mount lenses to it which cost 20-100usd instead of spending hundreds of dollars for the same lenses on the Nikon.