Personally I think there is something to be said for the older Triang and Hornby models, sure they are not as detailed as the current crop. But they were built to last, they are typically heavier than most new releases and the majority out there still seem to run fine or at worst just need a little fettling. I wonder if the same will be said of todays highly detailed plastic wonders in 50 years time?!? Of course the new Dublo models should last as like their forebears are mostly metal, the only potentially weak link may be these modern can motors, but of course they are at least easy to replace for the most part - well that and the cost of course as they're not cheap...
Happily collecting things all my life...