If the router in my SoHo network (a Netgear DGND3700) doesn't support IPv6 is there any benefit at all in enabling IPv6 across the server and clients in that network? The successor to that one (a DGND3700v2 makes mention of being IPv6 ready and supporting 6in4 but I can't find anything that says the original DGND3700 supports it.
[This may be more appropriate to SU but I think that its presence here can be justified also]
This question is highly opinion-based, but I'll give it a go anyways.
IPv6 is primarily developed to mitigate the shortage of IPv4 addresses around the world. As such, the only real practical application of IPv6 is when users would want to connect to a server which only has IPv6 support. Since you say your router doesn't support IPv6, you wouldn't be able to connect to the Internet using IPv6, or someone on the Internet to you. So it would serve (almost) no practical purpose to deploy IPv6 on your internal network.
For academic purposes, it doesn't matter if you can't route IPv6 towards the Internet. You could still deploy it on your internal network and use it for internal communication. It makes for some very interesting configurations and it really gives you an understanding on the challenges introducing IPv6 in a network. If you want to route to the Internet, you could also set up a 6-to-4 tunnel on another machine than your router, and route all your IPv6 Internet-bound traffic though that box (http://tunnelbroker.net).
From a professional POV I would say that without internet access it's pointless to implement. From a technical POV, go for it and have fun!
In the default configuration of most modern operating systems, IPv6 will automatically be enabled, if a router advertise to the LAN, that it can provide IPv6 access. This default is suitable for most scenarios, including yours.
If your current router does not support IPv6, then hosts on the LAN will not use IPv6 to talk to the internet. Once you upgrade your router, and the ISP starts supporting IPv6, then hosts on the LAN will automatically start using IPv6.
Not having an IPv6 connection towards the internet doesn't mean IPv6 is completely disabled. It just means it will only be used for communication between programs running on the same host as well as to some extent for communicating between hosts on the LAN.
Link-local addresses in IPv6 are often easier to work with than IPv4 because the IP address of a device is derived from the MAC address and remains constant regardless of configuration. And even if you don't remember the address, you can just ping ff02::1 to find all addresses on the LAN.
