I have had one of these for a month or so now. The range is fantastic (even with 5GHz) as is the throughput, though the Ethernet bonding feature isn't useful to me.
However, I, like many other X8 users complaining in Netgear's support forum, have an ongoing issue with the WiFi in that devices still show they're connected but no data flows. And if you have a device that tries to connect to the access point, the router rejects it. Rebooting the router fixes it for a while. Netgear support has been very responsive and they've given me beta firmware, but the problem persists. It's especially aggravating for my DVR which goes back to an "unconnected" state each time this happens, meaning I have to go through its configuration again.
Netgear is sending me a replacement router to see if that helps. I hope it does, as otherwise I love this thing. I was able to disconnect a repeater I had running on the other side of the house as I didn't need it anymore.