If you ask TalkTalk will tell you that the 2 routers are functionally the same. Although the new Huawei router does not have the channel optimisation that has caused issues with the Sagemcom. TT don't seem to have committed one way or the other as to that being a "future enhancement" for the Huawei router.
But you don't normally get a choice - and the routers are free anyway. As a "standard" end user, you probably wouldn't notice any difference anyway.
Also, there is no automatic 30 day reboot with any TT router. Individual routers may have individual faults, remote management may have issues, channel optimisation may have issues. But there is no 30 day reboot "by design". There only appears to be one report of this issue on the TT community forums, and quite often the forum OCEs will send out a new router as that is quite often easier (and cheaper) than fully investigating what could well be a one off router fault. The OCEs are there as customer service reps, not firmware design and debug specialists.
Edited by iefbr14 (Sun 17-May-20 10:09:54)