I have one of these in my home theater setup and it works pretty nicely. At $190 this is the cheapest I've seen it.

Couple of recommendations...

1. Make sure you upgrade the firmware out of the box.
2. If you're using the wireless connection and your router is in another room then consider upgrading to high gain antennas on your router and a direction antenna on this box. The DSM-520 grades your connection on a scale of 1-100, and in my case these upgrades took my connection from high 60s to the 98-100 range.

I had one of these and returned it. You definitely need to upgrade antennas to use this wirelessly. I still felt that it had enough issues with format support and general usability though. Some other factors to consider:

1) The remote is really cheap. I always hear this about stuff, and I don't usually care, but for a tv-like application it's actually important. If you have a Tivo you know that it has a great remote. It's solid, fits your hand well, and does the right stuff -- it's a great remote. This is just the opposite, it's poorly designed, feels way too light, and doesn't do what you need it.
2) Almost every review says it, but it bears repeating, The software is USELESS. Figure in the cost of buying the twonkyvision media server. You'll need it if you use this long term. I think it's about 25 beans
3) Almost every review say this too, No Good Fast Forward. It's just plain too slow for anything other than skipping through short commercial breaks (and if you have a tivo it's not fast enough . If you stop a movie and want to resume it, you're out of luck. It's only 4x, so getting 45 minutes into a minute can take over 10 minutes. There is an option to make FF work as skip, but it doesn't work, why keep the feature in the settings if it doesn't work! wtf? It just tells you that it's not supported when you try to use it.
4)There isn't great support for a lot of formats, this isn't a shortcoming of this unit alone, but of all hardware based media players. AVI is just a container for about 9 million formats, you just can't support it all with a chip. But that means that you'll have to transcode all your stuff.

If you want to watch some vids you have on your computer, but not a lot of video stuff then it's ok. If you have a huge catalog (or want to create one), of all your DVDs and tv rips, then I'd wait for something better. However, f you want this for mp3s or slideshows, or mp3s during slideshows, then it's great. But if that's all you want to do get the DSM-320, which is older and not HD, but also a lot cheaper.

This technology is getting there, but they need a bit more time. And they need to invest in the product for real. They need to really think about the features, formatting of the UI, and physical and logical feel of the remote.

That's just my two cents.

Who uses the remote that comes with one of these? Don't you have a universal?

Couple of additions from my original comments...

o The FF function is greatly improved in the latest firmware upgrade (as is format compatibility), #2. It's still not perfect, but it's my understanding that FF/REW is not supported in the UPnP standard.

o TwonkyVision is definitely recommended. As #2 says, don't bother with D-Links software. Hell, they basically recommend using Microsoft's Windows Media Connect 2.0 in their install guide. I prefer Twonky's server though because it's so much more configurable. By the way, you can download a demo version of this software which terminates after 30 minutes... BUT if you install it as a Windows service then it doesn't (I bought the full version though).

o It works great with my Logitech Harmony 880 remote control.

o The case on this is standard component width, so it won't look weird in your A/V cabinet.

In summary, when I originally bought this there was a lot about it that I didn't like, and I did come pretty close to returning it. I'm glad that I didn't though, because pretty much all of my gripes have been fixed with the latest firmware.