Past and current leased cable modems for me:
1.32 years = Terayon TeraPro cable modem (not DOCSIS) on Adelphia (Excite@Home).
2.46 years = COM21 DP1110XB-N (DOXport) due to Adelphia's PowerLink DOCSIS migration.
3.33 years = Terayon TJ715X (came back to cable)
5.92 years = Ambit/Ubee U10C018 cable modem due to coax cable connection problems on the old modem.
2.17 years = Arris TM502G (DOCSIS 2.0; v02)
5.62 years = Arris 1672G (DOCSIS 3.0) due to speed upgrade.
? = Spectrum's E31?2V1? due to dying cable modem due to its very high (hundred ms) pings on 192.168.100.1, unstable Internet, and unable to connect to servers.
Bought a Motorola SB6141 in June 2013. Signed up for (then) Lite Internet from TWC, which was installed in July of that year. Moved to ELP when it was offered. Still on ELP.
Modem works fine for the level of service I pay for, especially now that ELP is 20/2 at $19.99 per month. Spectrum will not provide a "free" modem on the ELP plan.
My 1st Spectrum (then Insight) modem was a D2 that was literally roasted and toasted by a nearby lightning strike,,,,,EMI pulse?
After that I purchased and used my own modem: a SB6183 with an Archer C9 router (Insight-Time Warner-Charter Spectrum)... Both of these were in Southern Indiana
Back across the river, here in Ky, I've had a Ubee DDW36C, a Technicolor tc8717t, and now a Hitron E31N2V1