Orbit Downloader makes it easy to download lots of files, but it's not really worth all of the junkware it packages with it. There are almost a half-dozen different programs and toolbars this download will try to add. Even the program, itself, is riddled with ads for other programs you don't want. The small boost in features isn't enough to justify this download.
This program throws more junk programs at you during the install than you could ever count. Even if you opt out of all of them, one or two will still randomly start installing themselves in the middle of the download. When it's done downloading all of those, Orbit Downloader will help you download other files. Downloads are a little faster than just using your browser, which is nice on slower connections. However, its bulk download support isn't better than what comes standard in Firefox and some other browsers. One nice add-on is the "Get It" button for easily downloading media files. That doesn't work in all browsers, though. It's nice that the program checks for program updates, but it was wrong more often than not. It often reported no need for updates when updates for the programs in question could be easily found online.
There doesn't seem to be any pressing need for a download like this. If you really need a program to manage your downloads, look at Download Accelerator or Free Download Manager. They'll all come with more speed and less junk than Orbit Downloader.