I bought one of these as well, and it works great with the Nexus 7. I haven't put it in the car yet, as I'm still doing my testing, but here are the things I've noticed so far.
1. My MP4 files aren't playing when using the Samsung Smart Hub app. It always says unsupported media type. I used handbrake and the ATV2 setting, which works for every other third party player I've tried (BSPlayer, ES File Manager player), but the Samsung video player chokes on them. However, if I use the same ATV2 setting, but choose MKV, they play. Definitely an issue with the Samsung player.
2. The Samsung video player cannot handle any HD content without stuttering. That's pretty much a kiss of death for me, because I'm not ripping the DVDs that come with my BDs just to have them for travelling. So, instead I use ES File Manager - the navigation is very easy and the player works great for all of my HD content.
3. If you want to play DVDs using the streaming app, then the Samsung video player definitely works and does the job perfectly. The only issue I had was getting a message about setting the correct region. All of my mobile devices can play DVDs that way (HTC One X, Nexus 7, iPod touch, and iPhone 4s).
4. MP3s play great using the Samsung video player.
Those are really the only things I've noticed so far. I don't have any other media types to try, because I only use MP4 and MP3, but for me this device will do exactly what I want - have a mobile media hub during our long trips, that all of my mobile devices can use.
If you visit the Samsung ODD support website and read the manual, and watch the videos, setup is a breeze. First thing - make sure you already have a USB drive/stick/etc with some movies or songs on it, because the SmartHub will choke when you try to navigate around in the app. I have a 32GB SD card (Amazon Basics - cheap but works great) and a SanDisk MicroMate SD reader plugged into the Hub, and it works great. External USB hard drives work, too - I've tried two different 2.5 SATA drives and both had no issues. After you set it up, plug the USB drive in before doing anything else. I didn't bother with the included setup CD - I just connected the SmartHub to my home network via ethernet cable, let it acquire an IP, then I used IE and browsed to
http://smarthub. I could set everything up that way, including doing a firmware update. My device came with A00, and A03 was available, so I went ahead and did the firmware update. Once that was done, I changed the SSID and password (the default SSID and password is on a label on the bottom of the device), changed the SAMBA sharing password, then I disconnected it from my home network and rebooted the device.
Next, I changed my Nexus wireless network to the SmartHub's - that's very important, because you can't use it at all unless your mobile devices and the SmartHub are on the same subnet! I think that's the biggest issue with people having problems getting things to work. I started the Samsung Mobile Smart Hub (previously downloaded from Google Play), set my SAMBA password, and I was up and running.
I don't think I'd use this for my home network streaming/playback, because I already have things in place that take care of media, but I don't think there's a better media hub type device for travelling.