Just installed the latest from Brainslayer and I'm very pleasantly surprised after having used tomato and shibby for a while.

ftp://dd-wrt.com/others/eko/BrainSlayer-V24-preSP2/2012/03-19-12-r18777/netgear-wndr3800/

Not only is the gui very light and fast but there are features like the 3g WAN connectivity that are a pleasant and welcome addition.  I thought I had to go with Shibby, but that's not necessary.

The ipv6 tunneling isn't quite so friendly, but there is a nice script example out there that did the job for me.

http://www.dd-wrt.com/wiki/index.php/IPv6_setup_Hurricane_Electric_Tunnel_Broker

In short, i'm impressed.  It's doing what I want and the processor is much faster than my old 3500L and I have the 5ghz band to use.