I think you might be suprised by a) how much work some people do with things
like destruction testing. I've got email from people who've done things like
7 day SMP and floating point torture testing on 4 CPU boxes. I have accounts
on several very large Linux boxes for doing tracing and kernel gdb probing
under odd funny cases
The Linux vendors also do a fair bit of work (some at least) to ensure the
entire package they ship is stable.
Alan