There an issue you had with your device? You just dumped DLink because they haven't released FW or IPv6 support sooner that you'd like?
Just because they haven't release support for IPv6 at this time doesn't mean they aren't working on it or thinking about it. There are other factors in development and releasing FW and features for products and doing that in a timely fashion.
I would also venture to suspect that IPv6 support will not be seen greatly at the home end user level till most other Corporate, Enterprise levels have implemented it fully or mostly there first. IPv6 isn't a requirement as of yet for home end users to connect to the Internet and not having it doesn't interfere with current connections. The IPv4 addresses that are running out are in question for the Major OEMS, Corporate, Enterprize and Internet backbones. Those have priority and should be working to take action to get IPv6 supported and going. I believe once they are fully up and running on it, then I'm sure the home end user will see more and more support for IPv6.
Well raising sales is one thing however if the devices isn't supported on the network fully, seems like a waste of time. Specially when there are other factors out there, How about SW support? Not all browsers support it at this time. I presume they will in time.