Jerry is sending me the demos of the 13, 11, and 10x3 for this weekend's meet in San Fran, so get on over there if you'd like to hear them.
That is certainly true AFAIK of the Sensa-style soft customs. For these acrylic ones, I don't see why they should have any worse (if not a better) life expectancy than universal IEM's. Even if they only lasted say, 4 years, you're only talking about $100 a year for great sound
I know a couple of people who have owned UE10's for over 5 years, and they are still working fine FWIW.