Hi
A lot of the swapping is indeed just keeping costs down, certainly for the likes of the Netgear, who aren't worried about matching chipsets to DSLAM given the countries the models cover, and the vast majority of their customers know nothing about chipsets and the potential benefits (real or imagined) of matching chipsets in the modem to the DSLAM. The D7000 has most likely had it's one and only production run which wasn't even made by Netgears own production fabs, they outsourced it and from what I saw it was made as cheaply as possible.
The D7800 will just be another production run with the opportunity to market some higher Wi-Fi speeds that the Lantiq chipset will theoretically support and that no one will see outside of a test lab! Broadcom will come out with another chipset theoretically supporting faster speeds again, and so is born the D8000.
Manufacturers like Netgear are treating routers/modems as a subscription model, the idea is to keep getting people to replace them by having a continual stream of 'new' models which are not made to last more than 6 months or a year before they obsolete them.
Regards
Phil
You have just described 90% of IT Industry and modern day consumerism in general
No matter how cheaply you describe it in your opinion, myself and several others own it and it works great and better than any other VDSL Router I have used and tried and have tried 5 so far, this is the only one that does not have any issues for me and works well for both me and my family and my needs.
Some of the Netgear devices get lots of firmware updates and some get hardly any.
If there was a great dedicated VDSL modem out there other than the HG612 I would have probably bought that and gone with a non VDSL Router, probably the Cisco business one plus separate Access point. But there isn't atm.
The only other ones close with features is the TP Link which I think some people are holding off until it gets a firmware update or the ASUS DSL-AC68U which has had a sordid past with it's Mediatek chipset and it's numerous firmware updates that have either failed to fix issues or introduced new ones, that being said the latest firmware update apparently seems to be working well for a lot of people now, especially on Huewei Cabinets.
I still contend that the combined VDSL modem/router market is mostly crap, we need a lot more competition in this area really to see better models.