It may be just me, but I noticed that Orbit Downloader has been downloading more slowly than Reget. Speeds for the same file does not top 100KB+ for Orbit but goes all the way to 170KB+ for Reget. I'm using RS Premium btw (Thanks Prem, hehe).

It may probably be due to the max number of simultaneous connections; Orbit has max 10, Reget has 15 (Custom setting). It may be due to that. Try changing your download manager or changing its settings to more simultaneous connections.