Back on 15 Jan I posted my experience of using 330/30 where I mentioned I'd found the Asus RT-N66U couldn't handle the speeds but was monitoring developments in the firmware.
Since then I installed version 22.214.171.124.374.38_2-em of the Asuswrt-Merlin firmware which has enabled (re-enabled?) Hardware Acceleration and the router has now successfully been running at over 300Mbps, and the SamKnows white box monitoring shows it's consistent (compared to other routers I've tested).
I've now upgraded to the 374.39_0-em version of the Asuswrt-Merlin firmware and the speeds are still as high.
So after over 12 months of trying the Asus RT-N66U on and off it's now finally working to maximise the 330Mpbs speeds and I'm going to stick with it for the foreseeable future.
But my original comment was about the 330/30 experience, as was asked for in the opening post. And my experience over the past 20 months has been that not all gigabit routers can handle it, and that firmware updates possibly haven't been tested for the faster internet speeds because the developers and most of the wider community don't have these speeds.
[Edited to correct date to 15 Jan from 14 Jan - thanks BatBoy for correction]
Edited by fttp (Mon 10-Feb-14 22:09:26)