About a year ago I bought about 8 different streaming devices, one by one, and returned them all. I ended up buying a PC and running an HDMI and a USB cable (USB for my IR remote receiver) up from the basement. In most cases it was the user interface that I couldn't stand. I have a gorgeous TV in a pretty nice living room and all of the solutions felt like they were 2nd rate walmart jobbies.
I didn't try popcorn hour or other media tanks because I had had such bad luck with every unit that I found in stores, and wasn't sure about returning a NMT. (Likely could return it, but would probably lose shipping, etc).
That being said, I've always wondered how a NMT like popcorn hour would have worked out. They sure seem awesome, powerful, and customizable. If you do get one, let us know what you think.
Next time I need to replace or upgrade I will definitely revisit them.