Hello there,
I was googling for Raysource that came across this forum and thought my experience with both the site and the program would be of any help to you
I am not Chinese but funnily enough like their dramas very badly because of which have to download files from fs2you.com using Raysource from time to time. Unfortunately I do not have Spybot installed and avast! (an AV and on-access scanner) and Windows built-in firewall are responsible for my Win security instead. Anyway, I have downloaded files from that site and nothing bad has yet happened (though I won't guarantee any thing nor do I recommend you risk anything). In my opinion, it's a sort of a P2P thing (client and network) working ONLY in IE as it both downloads and uploads at the same time (while it shouldn't do so as a file hosting service) and its speed changes from time to time, even reaching zero for a minute or so. OK, let me attach some screenshots to support this opinion:
The site, the progress bar, and raysource running :
(bad picture removed)
And this is the info shown while you move your mouse on the raysource accompanying task bar icon:
(bad picture removed)
And this is what you get if you open a fs2you link in firefox:
(bad picture removed)
I cannot be sure if the site is really harmful or not as neither my AV nor Google report it as being such a one and I myself hasn't faced any trouble using it (knock on wood!) yet but this doesn't guarantee it being absolutely clean as the way it handles and treats your downloads (like a BT client or emule) is rather strange
Anyway, these were all I have experienced using these and hope they are of any use to anybody
p.s. I usually uninstall raysource whenever I do not need to download from fs2you.com.