They're just distasteful and annoying. Check out Kim Kardashian hanging out on their home page. They make you wait for a download. And I've had problems with downloads always stopping at the same point no matter how many times I tried.
I'm sure an adblocker could take care of things for you if you don't personally like the celebrities (the ads are definitely more tasteful than the GET RIPPED IN FOUR WEEKS ads i see on Mediafire now).
Technically speaking it's still a good service, and i've had nothing but good experiences with downloads from there (mostly because i automate them). I accept that you can disagree but i wouldn't go as far as "terrible".
I'm probably biased because i love the song, and Kim Dotcom donated to earthquake relief in my city...
At the risk of appearing to be a fool, I can suggest that if you are doing enough DLing that the wait is a problem for you, you might want to go the Premium route. I'm an anime buff (as well as other stuff), and have a yearly subscription with them and with Fileserve. Blistering fast DLs, no waits or ads, YMMV...
The whole point of the wait on various download sites is to throw advertising for Premium on you. They also make you scroll past “buy premium” buttons and such to reach the download button on some sites. I think you can assume that if someone is complaining about the wait time for a download site, they have already considered and rejected buying Premium.
