I've been transcoding my media collection leaving my PC on overnight over months, it's great. My biggest issue is client support for native playback of AV1, naturally.

For what it's worth, AB-AV1 [1] is a pretty awesome tool written in rust which compares random samples from a file at different parameters based on their VMAF score [2] (algorithm from Netflix for human-perceived visual likeness), choosing optimal parameters to save as much space as possible with the loss you're willing to stomach, on a file-by-file basis.

Small plug: I made a nice little python GUI wrapper for ab-av1 [3].

[1] - https://github.com/alexheretic/ab-av1 [2] - https://github.com/Netflix/vmaf [3] - https://github.com/Loufe/AB-AV1-GUI