My sansa clip plus died and I'm looking for a replacement that uses the same subfolder options. I organize my mp3s by genre > artist > album, some times having songs in the artist folder and the genre folder as well. On the sansa clip if I hit play all on the genre it would play every song in every layer of that folder, all the albums and all the songs in the sub folders. The sansa clip jam will only play the folder you select, so if you select genre it will play only mp3 files in the genre folder and ignore the subfolders.
Everything else is secondary. As long as battery life is 10+ hours and I can charge and edit the folders via usb I'm happy.