I am actually in the trial period right now. I've been getting 150-300 down / 20 up with the newer Arcaydan gateway. I had to experiment with different locations to get the best speeds. It's sensitive and even a few inches makes a difference with speeds.
The default settings accessible to the user are limited to basically just changing the network names, passwords and bands. I don't have an external router hooked up.
The Internet tends to drop a few times a day, mainly when I'm watching HD YouTube videos. Restarting the gateway brings it back. My signal level is 4 bars next to a window..
I'll keep trying it for the rest of the trial period but I'm not sure if it will be a reliable alternative to my cable internet. I work from home and can't have dropped calls with clients. It's certainly cool technology, with no wires needed besides the power cable.