I too love j downloader, but how do u download everything with JDownloader, Its not an automated process after clicking a link to download right, every time we must start after booting and if we must download we must copy the download url/link and then proceed with JD, so this is a long process. I was facing an issue to download video from this site:
http://www.watchcartoononline.com/anime/one-piece-english-dubbed-guide, then I figured I cannot copy link and I found an alternative ext for firefox called Download Helper, which worked well. So what I suggest is not all download managers are perfect, each one are crafted for a particular action, say download helper is the best for video downloading, so if u want to prove it wrong let me know how u download everything with JD?