Has the latest firmware update resolved the DHCP/DNS problems and bad behavior with BitTorrent-protocol applications?
Don't know, sorry. I can tell you I don't have any problems using uTorrent with my 3 Mbps connection. But I limit connections to 200 and only have 4 concurrent downloads.
I'm trying to find a modern replacement for my venerable WRT54GL (running dd-wrt), but it seems like there's something wrong with every single dual-band/dual-radio gigabit-switched consumer router on the market.
The Linksys WRT610N/E3000 has a lousy 5GHz signal and is hot enough to cook an egg.
The Netgear WNDR3700 has (as above) buggy DHCP/DNS and freezes up when under multi-connection load.
The D-Link DIR-825 has a mediocre wireless signal as well.
The more, faster, stuff you cram into a small package that doesn't have enough air moving through it to remove the heat, the hotter things are going to be. The hotter things get, the more chance of problems and shorter product life.
A single band N radio uses more power than a G radio. Two radios use more than one radio. Gigabit switches run hotter than 10/100 switches.
If you are going to push a router hard with constant high-speed traffic on wired and wireless networks, you either need to supply some cooling with a laptop cooler mat, use separate components or both. An easy place to start is to get the Gigabit switch out of the box into a separate component.
There is no router I've tested that stands out from the pack in the 5 GHz band. None of them have been able to reach my weak signal test locations that can be reached using their 2.4 GHz radios. 5 GHz signals are attenuated more than 2.4 GHz when passing through walls and manufacturers aren't willing to put the power amps in to compensate because most consumers buy on price.
I feel like my needs aren't all that complicated, but it seems increasingly as if I'm going to have to pony up to a business-grade device if I want something that works properly and does what I need.
You probably won't find better performance. But you might get better reliability.
Speaking of what I need:
1) Gigabit switch
2) Dual radio (planning to herd all N devices onto 5GHz and retain 2.4 for G devices)
3) Ability to have ~2,500 open connections for BT and not die
4) Properly-functioning DHCP and DNS (I address and connect to network machines by name, no interest in doing so by IP)
5) Handle a 10Mbit WAN connection
I would get a separate Gigabit switch and not count on 5 GHz unless you have a small area to cover with few walls, preferably not brick.
I can't speak to your DHCP/DNS issue, since I stopped trying to fight that battle awhile ago and just use mapped drives and static IPs for anything I want to be able to reliably find on the network.
Finally, handling a 10Mbps WAN isn't hard. All current-generation products can route at well above that speed.