After narrowing down the replacement router that I wanted to either a Netgear WNDR 4500 or an Asus RT-N66U, I bought an RT-N66R from Best Buy last Saturday. It really wasn't until I got it home that I noticed it wasn't a "U". Since I couldn't find a reference to that model on the Asus website, I called Asus tech spt/product information and was told by an Asus rep (who didn't hesitate in his answer) that the only difference between the "R" and the "U" models is that the "R" is sold by retailers such as Best Buy. That sounded great. However, the firmware version that the R came with is 22.214.171.124.176, and doing an update check with the router's web administration GUI states that "The router's current firmware is the latest version." Yet, we know that the latest U firmware is version 126.96.36.199.220. When I went to the Asus download website today, I found that both the R and U were listed. For the RT-N66R, no firmware updates are listed as available, and the utility software is shown as: ASUS RT-N66R Utility version 188.8.131.52, The first version of utility for ASUS RT-N66R. (For the RT-N66U (VER.B1), the utility software is ASUS RT-N66U B1 Utility version 184.108.40.206, The first version of utility for ASUS RT-N66U B1.) Issues that I've found so far with the R are: 1. The HTTPS SSL admin web page freezes. 2. The Save Setting selection goes and HTTP 404 Not Found page for http://192.168.1.1/Settings_RT-N66R.CFG Since it's evident that I need to upgrade the firmware to fix these issues, I might as well try the Merlin ASUS RT-N66U 220.127.116.11.220.18b while I've still got store return privileges. I'll let you know the results. If it's fully compatible, I think that the R should maybe be rolled up into the U subforum. I suspect the R could outrun the U in sales from big box stores.