I've been using 5D3 Magic Lantern RAW for a few years now and it's my personal gold standard for image quality as I'm very familiar with it, can predict the results I'll get in various situations and have developed my own look that I like using in post. I do a lot of documentary and corporate stuff and wanted to do more handheld, so I got the GH5 for its IBIS, 10bit V-Log, 4K and general ease of use. Although the GH5's colour is an improvement on its predecessors, the 5D3 is nicer looking to me.