So in general, both of the products performed well. They have an attractive-enough user interface, can access lots of online content, and can play back your own multimedia files as well. But in order to get traction in the family-room, these boxes have to remove the friction (how's that for mixed-up metaphors?).
The point is, for these devices to fit in, their usage needs to be seamless and fluid. As it stands now, each has a wide selection of content sources. But each source has its own user interface with different colors, menus, fonts and button-mappings that are often inconsistent between them.
As an example of friction, when exiting a content source like Hulu, you'll often get a confusing pop-up asking "Are you sure you want to quit?" (Figure 11).
Figure 11: Hulu Plus prompt
"No I don't want to quit. I just want to get to the Roku main menu!". These pop-ups only highlight the fact that the content integration into the products as a whole is lacking. You get the feeling that each source is its own little island and you have to mentally change gears to move from source to source.
On the WD TV Live, every time I select a new content-source, I get 10 or more seconds of black screen that makes me wonder if I accidentally hit the power button. I should be able to fluidly move in and out of all of these services without any black screens, annoying pop-ups, changes in remote behavior or changes in the menu. The Roku was a little better coming in and out of the various services, but the basic problem is still there. Every "channel" has its own menu style and interaction.
The reason for the slowness is that the content sources are actually "apps" that are downloaded into the limited memory in these devices each time you select them. Since memory is small and CPU power is low to keep costs down and app loads depend on how busy the server they are coming from is, switching apps isn't speedy.
As for the difference in look and feel, let's just say that the content and app providers have a lot more power than either Roku or WD. Apple may be able to tightly control iOS' API and keep tight control over which apps make it into the App Store. But Roku and WD are probably just happy (and relieved) to have support for these popular services in any form that they can get it!
Many users will also want to use these boxes in conjunction with normal satellite, cable or over-the-air broadcasts. When you do that, you'll have to switch TV inputs and then use another user interface that will be yet again completely different. It will all work, but you'll have to consciously switch gears between online and over-the-air content. And then when you've selected online content, you'll be reorientating yourself each time you select a new content source. Ouch.
That's the friction, and that's the problem that Steve Jobs believed he had "finally cracked" before he died. Time will tell if Apple is able to come out with a new version of their AppleTV that solves this problem. But for now, it's a real issue with all streaming media players.
Rant aside, both the WD TV Live and Roku 2 XS do a good job of playing back content from their supported partners. For $100, if you just want something to access Netflix, Hulu Plus, YouTube, Pandora, etc. from the comfort of your couch, either one will do. Just make sure you check the list of supported services before you buy, since each box supports some services that the other doesn't.
That said, Roku's list is much larger than WD's and you can also play Angry Birds on it (the XS, at least). The downside of both (and for this product category in general) is that you're just going to have to put up with the varying user interfaces.
A big question mark for the future of all these devices is content. Without a large selection of online content, they're much less appealing. (Just ask Google TV owners...) I like being able to access Netflix and Hulu (assuming that my buffering issues were just transient) on both of these boxes. But Netflix just went through a major misstep based on rising costs of content. And Hulu has its own issues that are causing uncertainty about its future.
If you want to play your own content, these products can also do that. But the WD is miles ahead of the Roku is format support and you don't need to have all your files on an attached drive. However, both products will have you navigating directory structures and choosing movies based on file names instead of using metadata such as title, actor, year, director, artwork, etc. That doesn't live up to my current capabilities of full IMDB-Based metadata for my movies. So I'll keep looking for a player that can better handle local content.
If I were to pick up one of these boxes for online content, I prefer the Roku. It uses a fraction of the power, has a simpler interface, a less-busy remote and a wider selection of online content. And if I go off into my rant-mode again, maybe I'll just calm down by playing a round or two of Angry Birds! If you want a good (but not perfect) combination of online and local content playback, the WD TV Live would be your choice.