I received the AWUS036NH yesterday and here is my experience:
I have used AWUS036H 802.11g units with outstanding results for over three years. I have these in use in three locations including roof-mounted and have turned on friends and family who also have used them with good results.
What makes the 11g units so popular is the exception receive sensitivity which is achieved through the overall combination of chip, circuit board, RF and antenna design. I think the reason why nobody else has been able to duplicate the achieved level of performance despite using the same chips and similar board layout (copy-cat) and antennas is the attention to detail that must be given to every single detail of the design. Those few of you who have worked in microwave devices know what I am talking about.
This .11n unit uses a chip from a subsidiary of Mediatek, another of the Taiwanese companies that have excelled in wireless. I would expect the performance to be competitive, which it is, but have found it to lack the same outstanding receive sensitivity of the AWUS036H.. to be more exact, the unit is about -3dBm or roughly half the receive sensitivity. That is a major consideration depending on your intended use.
If you are looking for the best War Driving tool, stick with the AWUS036H or consider the AUS036NHR. However, I have no experience on the latter unit and reviews are mixed.. drivers may be a problem as well as drop outs.. judge that as you may.
If your intent is to achieve increased throughput to support video, gaming, higher rate home/office computer networking, then the conclusions change much more in this units favor. I did a test of a connection with a Linksys 802.11n AP through two walls and about 200 foot distance.
The receive signal level was about 30% lower than the AWUS036H but the unit was able to crank up the bandwidth of a 4GB file download using Comcast as the Internet service provider to 2-4X that of the .11g unit. The speed of this unit is compromised for range: it is not a fully compatible .11n unit because it lacks matched multiple antennas.
Instead, this is a subset of 802.11n that uses advanced .11n signal processing to achieve higher throughput despite lack of full signal diversity of matched 2X and 3X antenna units that achieve best case throughput of 150Mbps, 300Mbps and aggregated channel bandwidth up to 450Mbps on some units available. (the best case bandwidth is seen only on Mars on a day without sandstorms).
BTW, I didn't use the CD version of software - downloaded the latest before plugging the unit in. Windows 7 x64 recognized the unit and I was able to connect prior to software driver and utility installation. The utility provides some useful features such as WPS sign-in and a more thorough set of information to make it an advantage.