I've been using it almost a week and I'm very happy with it.
I did have older zwave switches so I'm slowly upgrading them, but I didn't purchase a lot yet so it's not a big issue for me.
Wifi signal is MUCH better than my TP-Link even after I got bigger antennas. None of my security cams drop out anymore, and I can get a wifi signal sitting inside my car in the driveway which I couldn't do before. It might be my imagination but I'm not getting near as many drop outs when watching Netflix movies or browsing the web.
I also LOVE that I can go into the wwrt advanced settings while still keeping the regular web ui for normal day to day tasks. You have done a good job on balancing the two IMHO.
Great job guys! Can't wait for the new updates as they come out for the router and the iPhone app.