I previously used SABnzbd. I liked the way the files were handled. First you download everything to a sub folder of 'Incomplete' folder. After checking the files and repairing them, the files get moved to a sub folder of 'Complete'. There the files are unpacked and if that was successful the rar files are deleted.
The changed behavior if I compare this with Alt.binz is that SABnzbd moves everything from the Incomplete folder.
Alt.binz leaves files in the Incomplete (=Download) folder and that makes a really big mess. So my request would be to move everything in the download folder to the unpack folder and delete the folder in the Download directory.
I hope I made myself clear enough, else I will explain it again to you.
But you made a really nice program! I love the implementation of NL SS!