I believe there were some other modems used during the initial trials, but these days they are using a white
Huawei MT992.
They are locked and no access to stats.
During my daughter's install the engineer replaced the existing NTE5, plugged in the MT992 and attached it to the ISP provided Fritz!box.
No they don't take away the old hardware or even ask about it.
The choice of combined units to be able to get stats is very limited - practically zilch.
If it were my line I'd be saving up for an ASUS DSL-AC88U Whilst ASUS has a good reputation for routers, they havent been so good when it comes to modems for which they have tended to use MediaTek chipsets. The newer DSL-AC88U has a more familiar BCM chipset, but unfortunately is rather pricey at circa £200.