I'm very happy with it. There was an issue with HDMI hot swapping. I.e. pluggin in/unpluggin an HDMI cable while the pc is on, but I updated to the latest BIOS version and that sorted it out. (Let me know if you get one and need to do this, as I had to find the flash software separately as a result of my operating system)
I'm running Windows 7 Ultimate 64-bit on it and it works flawlessly. Gets a good score on the build in benchmark thing, except for the CPU, but that's not a huge surprise.
I'm running XBMC on it and have it connected to a 32" samsung LCD. Works perfectly and outputs the native resolution of the LCD. The wireless networking seems to work well, optical digital audio is good.
If I had to find something wrong with it I would say the fan can get a bit loud at times when you are doing CPU/ graphics intensive stuff. Small package so nowhere for the heat to go I guess.
If I was presented with the same choice again I would buy it without a second's hesitation. It's perfect for what I'm doing with it. (HTPC)