The only free site left that I have found usable is Uptobox that SamCook provides and I wish the others would too! I used it for the first time the other nite and the download speed was better than any of the premium sites I have used so far, a few minutes per 500Mb slice. K2S and the others are taking 3hrs or more per 500Mb to download making them unusable for anyone with a life.
Considering the amount of porn you can get from here by subscribing to filejoker it is sort of worth it, and there are a few other places that have file joker links on them; but I agree it's not as widely used as something like keep2share though
I don't know if they've tweaked it recently but it seems a hell of lot faster now than before.