I've gotten into the habit of manually setting the priority to high on any file more than about 80% done, and setting it to auto swap a4afs, but it seems to me like it would be generally desirable behavior for aMule to handle this automatically. (Most of my downloads are automatically high priority, so setting a file to 'high' when it hits 80% or 90% wouldn't do it. It would have to be something more than that.) It makes more sense, all else being equal, to favor downloads that are nearly done - if you have 10 gigs of stuff in your downloads, and 2 gigs of it are downloaded, wouldn't it be better to have 20% of your files completely downloaded rather than all of them 20% downloaded? It's no more efficient from a network perspective, but in terms of actual use, it's way more effective.
I'm not sure how huge a difference it would make but it certainly annoyed me to see files that were 98% done sitting there, and clicking on them to see that they had dozens of a4afs listed. I have a lot of stuff transferring and I imagine that this is a problem that becomes bigger the more files you have waiting; anyway, it seems to be a problem for me.
So I propose that, when possible, aMule automatically favor files that are substantially complete. One completed file is worth a lot more than two half-completed files.