i am having the same problems, im currently using an older realtek driver and it seems to help a little. i will try the driver listed above to see if there is any improvement.
Update: seems to be working fine now, hopefully asus can update their drivers soon
They just launched this router in Singapore last weekend at the IT Show we had here.
I too haven't seen it online yet, I did however... manage to get my hands on 1 :D certainly an upgrade from the one provided to me by my ISP.