[marcosdumay]

If it's that bad, it should be easy to discover what is fastest.

But the way too common situation is that you look at a program under development and tell people "no way, that list will be too large to keep searching, you should design it around a hash set", and people reply something about premature optimization and keep going, then it gets released and is too slow to use so you get to rewrite all their code under pressure.