A friend of mine had a Sylvania Superset console for years (it was the first TV he and his wife had after they were married in 1982, IIRC). It worked well as long as it was working, but after about 15 (?) years it developed serious problems and was replaced a few years ago by a Toshiba 32" table model. My friend now has three Toshibas in his house, BTW, that all work well, although one of them blew a couple ICs shortly after he bought it. The repair was done under warranty, however, and ever since then the set has been working fine.
As to his Superset, I'd say 15 years (this is only my conservative estimate, as I really have no idea how long the set worked before it finally died) was a long life for a TV made in the early '80s, although I have no idea how much the set was used during the time my friend owned it.
I am almost afraid to mention this, knowing how AK members (myself included) feel about gutting older TVs for the cabinets, but here goes anyhow: When his Sylvania Superset finally went west, my friend gutted the set, threw out the chassis (please, no flames) and converted the cabinet to a bookcase or entertainment center (again, I'm not sure which).
!!! But this friend of mine is an accountant, not an antique TV collector (though he does have several antique automobiles, so one would think, would one not, that he'd have a feeling for the value of things made 50+ years ago) and certainly not an electronics expert, so I guess he can and should be excused for gutting a 15 (? again) year-old color TV for its cabinet, an act I know makes us AK members gasp in horror.
(I've seen it happen several times in this and other AK forums).