Comment by sumtechguy

For cover art you can control it from options->options->cover art. There are also a couple of plugins for other sources.

There are a few items in there to control if it scans external or overwrite. Recently went thru this as apparently for some reason I had totally disabled it. Think I was trying to speed up scanning as it would download every artwork for a large group into the temp folder. I usually force it to make an external file. I pick what it suggested 'cover'. Then use something like fileoptimizer to recompress the jpg/png it comes up with. I do that because I like to embed the images. And much of what is out on the net is optimized for fast editing not 'archive'. I use mp3tag to put it back into the tag.

Scan is hit or miss. I have fed it whole albums and it will somehow find 3 other albums with some of the songs from that one. That could be because of how I have options->options->metadata->Prefered Releases set. That slider bar thing for some reason I can not wrap my head around. It is good for when you come across one of those items where someone else tagged it as 'weird al' (everything is weird al if it is funny). I have been slowly getting rid of that stuff but want to find the original album to buy. Musicbrainz can be good for that sort of thing. I have also had decent luck with it if I pre-add the albums then scan. It seems to find things better.