I recently moved and are now a customer of Vodafone Germany with the offer "Red Internet&Phone 100" via cable (DOCSIS). I was not really satisfied with the crappy router (Vodafone-branded CGA4233DE from Technicolor) which Vodafone provided. The main problems were:

• The CGA4233DE restarted randomly every few hours. The complete reboot cycle then takes around 5 (!) minutes. This was just unbearable if you still have to work from home because of COVID-19.
• I could not configure a custom DNS server (PiHole) in the DHCP response for blocking ads. I could have worked my way around this by setting the DNS server on all devices manually.
• There wasn't a way to open any IPv6 ports either, even when the original Technicolor Router can do this! So Vodafone intentionally blocked this functionality. Even when I don't need this currently, I still hate all ISPs which are removing intentionally features in order to upsell you something else.

Calling the Vodafone hotline is basically just a waste of time, so I never even tried and instead decided to buy a used "FritzBox 6430 Cable" and to make use of the "free choice of router"-law in Germany. This worked surprisingly smooth and the new router didn't have any sudden reboots so far.

To my suprise, I now can get real Dualstack, i.e. a full IPv4 address! I almost missed this, because if you set the configuration of the FritzBox to "Native IPv6", then you will get a working internet connection with DSLite. You have to change it to "Native IPv4", then you get a full IPv4/IPv6 Dualstack setup!