In addition to what Yrcanos said:
FileFactory and, I presume, Depositfiles have also caused file corruption *for some people*. This may also be due to the nature of file-sharing sites.
Also, your download speed for the direct file downloads will depend on 1.) your overall nominal download speed, 2.) the number of files you are trying to download at the same time, 3.) the CPU internal clock speed as well as the internal bus and I/O speeds of your computer, and 4.) the R/W speed of your storage device (HDD or SSD).
Along with Yrcanos, I'd recommend using either the Frogster-Online or Frogster.de links.