I still use a Terayon modem. I've had it for at least 4 years or so now, & never had a problem with it.
Before the Terayons, ntl supplied various other cable modems, including the 3com & the Motorola Surfboard. They currently supply Ambit modems, badged as "ntl:home" modems.
The Terayon isn't the best, but it isn't the worst. 'Tis just a cable modem, nothing special about it or the others.