I've been using isyncr for about a year and I think it is great. It won't sync any DRM protected content, but it does a great job with non-DRM music. I loaded the WIFI app add-on and my music syncs with my PC while I'm asleep. I can recommend isyncr as a good solution and for me the convenience more than offsets the cost. Note that isyncr does require a program be loaded on your PC, but it is quite efficient and only uses resources when it needs to.