Game DVR also produces excellent quality with all setting at the highest level, with the bitrate at 42Kbps. (I have to switch to AVC if I know I'm going to edit with Vegas Platinum 13, since HEVC isn't compatible) I don't have much experience with Shadowplay since it's on my work PC and I don't game much on that one, but ReLive has an adjustable bitrate slider and I usually use around 50Kbps, encoding with HEVC. It also helps that they're free, with the quality being as good, if not better, than paid software. There are advantage over Action!, in that you can record at a higher bitrate with ReLive, which makes a big difference in the quality, and the file size of course. However, AMD, Nvidia and Microsoft have respectively improved ReLive, Shadowplay and Game DVR enormously over the years. That was until I found Mirillis Action! on sale at Steam a few years ago and I've been using it ever since. I first started with Fraps, until the file sizes just became to large (avi) and then moved on to a trial of Bandicam which was really good, but rather expensive.

Reddit what is bandicam