less Idle time with busybox ash as bash vs bash

[James Hanley]

We had some bash scripts that we converted to use busybox ash as bash
(removed any array constructs) and when comparing the two scripts - it
seems that running them under busybox yields less idle time compared
to bash.

I was expecting that busybox would (itself) take up more time simply
because of vfork, but yield more CPU time overall since there would be
less overhead as a number of the applets would not fork&exec.

Is this expected behavior that busybox overall yields less idle time?
-Jim