Per the recent news about TiVo and Amazon Unbox integration, and a $15 dollar credit for trying it out before April 1 (or so), my wife and tried it.
First, at least TiVo series 2 machines don't download very quickly, a problem I've already had trouble with when trying to download things from the TiVo directly. It's not much better with Amazon Unbox; a 42-minute TV program took quite a while to download, two hours at least. (We weren't obsessively paying attention.) This is definitely a TiVo problem, though, not an Amazon problem.
The quality was good, on par with or better than Best recording (better source signal), with a smaller file size. (Offline MPEG encoding can be a lot better than on-the-fly MPEG encoding by a chip designed to be cheap, not good.) The website is slick and reasonably useful; I can believe it might work well with a large library of media files.
However, after the initial slick experience, it came apart. We ordered the second and third episodes of the television series we were testing with, and I have not been able to figure out how to receive them. I've made repeated attempts to have the program downloaded to my TiVo, and it never gets downloaded. In frustration, we downloaded the PC version of the player, but we couldn't convince that to download the video either.
The good news is that we're not showing as consuming any licenses that we shouldn't be, but that's small comfort.
Bear in mind I'm a professional computer programmer, so I'm pretty sure I've tried several things most people wouldn't have thought of. Also, other than installing Firefox on my wife's computer I haven't really done anything to it, so even the "over-customized computer" scenario shouldn't be in play.
The only difference between the first and second order is that the first order was for one program, where the second one was for two programs in the same order. But what that would have to do with anything I don't know.
All in all, totally unimpressive to us and I'm not even inclined to try to finish my $15 credit, nor am I inclined to fuss with tech support over something so small. If you've got a TiVo, you may want to give it a try; maybe it'll work better for you and if it does, it's at least $15.
However, the usual major digital-distribution complaint is in full force: I have to provide the bandwidth and storage, I don't get a box or liner notes, I don't get a factory-pressed DVD physical medium (which doubles as backup), and for some mysterious reason prices range from "as expensive as a DVD" and up. Only higher-end DVD TV collections can charge $2 an episode, and as more DVD TV collections age on the shelf, an increasing number of quality shows are available at $1 an episode or below for the DVDs.
Before we realized it wasn't working, my wife and I actually briefly did the math on cutting off our cable service and going to pay-only TV (as cable prices rise this gets increasingly attractive), but at $2 an episode of anything that's not feasible. That's not necessarily a complaint, just an observation, but a flat $2 an episode is pretty silly. Last week's Survivor is not equally valuable to a first-season Cosby show episode, or other such TV Land classic.