An awful lot of us are having problems - you'd hardly expect every person with a problem to find their way on to this thread (there are bunches of other threads about similar problems). I think most people just give up.
We bought the box to use to watch HD television. It advertized itself as hosting Netflix, vimeo, youtube and Itunes. It only does the first three in a way that's compatible with spontaneous television watching.
We haven't had it long, I have absolutely no interest in attempting to set it up differently or better. Some day we'll get a faster connection and a way to hard wire ATV3 to our ethernet port (it's in a different part of the house - we have other things to do besides have people come over and install new outlets right now). I just wanted it to work (and it does, for Netflix, which is nice). It also works for streaming vimeo atmospheric videos, like having a fish tank or a set of nature documentaries in a doctor's office (I'm trying to make myself feel better about the $99).
Anyway, to anyone who happened on this thread before they purchased the thing, just view it as an accessory to your iPad. My old iPad didn't have enough storage to download HD films and keep them around for any length of time. So, I bought a new one with lots more storage (I suppose that's the point?) And, we do plan ahead for watching. Sort of like the old days of going to the video store (or having Netflix delivered). Instead of making a spontaneous choice of movie (which I would never do with this device, not from iTunes anyway), we decide what we're going to watch and I set up the downloads to my iPad while I'm asleep or at work on the T1 connection (works better just to do it while sleeping). So that's my work around. Low tech.
I view my iPad now as a remote control for the ATV3, to play iTunes. The iPad downloads faster anyway and sometimes makes a show (especially an hour television show) available in about 30 minutes. I was glad to read this thread and realize that people with much higher download speeds than ours are having the same (or worse) problems. Maybe throttling. Peak usage times are much worse (Friday nights, all day Saturday and Sunday). So I try to plan for that.
It was also good to know that every time we do anything different with the ATV3, we have to start our streaming over again. That explains a lot. So we let it go when it is taking time to download (and occasionally, it's a bit slow even on Netflix - that's probably our ISP), and revert to watching satellite TV or iPad youtubes while it works away. In future, I think we'll just use it for youtube, Netflix and iPad airplay showings. I sure hope Netflix sees the opportunity for themselves, though and makes more recent offerings available.
I am guessing that of the top movies shown on the ATV3 on start up, most will never be watched - but many will be rented and then abandoned in frustration. I'm glad I read the thread before deciding to try and watch something as low on my priority list as Hugo or that new Brad Pitt movie. The idea we had was that we might occasionally just stream some random thing we wouldn't otherwise have rented while doing household chores or working online - but that won't be happening. There's nothing wrong with being more deliberate in one's entertainment choices, really, but I do wonder how much money Apple makes from the movie distributors for simply advertising those films (probably a lot). Then, they make more money from people who are either willing to wait for hours to view a film or who give up on the project altogether.
I wonder if the film distributing companies realize that in many cases, this leaves a bitter experience and no desire to try and actually watch the movie? Perhaps the movies all suck and they don't care, either. It would be an excellent way of making quite a bit of money off of movies that suck (and the fact that movies keep stuttering and losing sound and then taking 30-40 more minutes to start again right at a central plot point is supposed to drive us back into the theaters? That's not going to work with us...)