I would like to have input on this as well. I am considering this receiver to drive 4 Ohm speakers as well (Polk LSi9, LSiC, LCi6). I have read a few posts of people using it successfully but I am worried it will not be strong enough for this application. I know about NAD but am concerned with quality issues and on a more basic level think the Rotel looks 100X better.
I was told by Rotel tech support that while some of their customers successfully use this unit to drive 4 Ohm loads they don't officially support it. And if I was to use it for this application to make sure there was at least 4" of free space on all sides. They said the reason it's not supported is the receiver does not have the proper ventilation. I am tempted to go this route as I could add a small 2 channel amp if needed to help with the load but would like to hear from people who have used it with success first.