I dont know about the server, perhaps for the holidays, they are more busy than usual, sounds like that to me. But as to most of the mods being on FileFront? Probably the best place would be the Wincustomize site. They are grouped by author and type and by date and several other ways. It is a wonderful site and much prettier than filefront. But it takes them 5 days to review the material before uploading it. I think that is the main reason. FileFront and also RapidShare allow you to get your files up quick and downloaded asap.
At least that is my opinion, you would have to ask the other modders why they use FileFront more, but that is why i use it, but i still like Wincustomize better. 
-Teal
