I usually prefer the lowest level at which I can write reasonably concise code.

Sure, I understand that - if I have doubts or issues with a module I'm using and there's no other module available, and I can go a level lower, I'll often do that (e.g. Lower-Level Serial Port Access on *NIX). On the other hand, it also usually means a steeper learning curve and potentially more caveats, edge cases, and portability issues one has to know about and has to cover. Anyway, my response was also meant in the context of the thread, i.e. adding more information for the wisdom seeker. I've had good experiences with IPC::Run so far.