New SDK5 version functionality looks great to me (rt-n66u).
One thing, though, I'm still getting:
Oct 4 13:26:43 kernel: eth1: received packet with own address as source address
I flashed back to 270.26b and still got this, so went forward to the new 374.33 and removed the wireless ethernet bridge and still get it.
Is there anything I can do to get a dump of the packet in question, like setting a router software variable in nvram? I'd like to see the MAC addresses in the packet header, specifically, along with the IP addresses, of course. Maybe there's a debug flag or debug level I can set to see what's going on with this? Seems like one should be able to get more information about this kind of thing?
Personally I wouldn't worry about these, unless you notice any particular problem.
That error message comes from the Linux kernel itself, so there's little that I could do to get more info about it - it's not generated by the firmware.
Might this have anything to do with STP? See:
https://supportforums.cisco.com/thread/2060349
Based on what I think STP is supposed to accomplish it seems to me it might be related (I'm guessing of course, and would think it has something to do with what your network topology looks like).