[j-pb]

How the heck to you hope to gain any insighfull metrics when you've got a cobbled together mess that you only half understand. For what it's worth you might only be benchmarking random code layout fluctuations.

I've seen research groups drown in their legacy code base.

The issue of juggling too many balls you describe is one you only have to begin with because the state of the art implementations are so shoddy to begin with.

Research suffers as much as everybody else from feature creep. Good experiments keep the number of new variables low.

[gmueckl]

Research code is not only written to measure runtime. Reducing the argument to only that aspect is not helping the discussion.

And you say it yourself: good experiments change a single variable at a time. So how do you check that a series of potential improvements that you are making is sound?