Note that you are confusing &mysub; and &mysub(); which are very different. (tye)Re: A question of style goes into these in some detail.
As for avoiding & on subroutine calls, that is, to a great extent, a style issue. Frankly, several of the reasons for using & on subroutine calls (avoid collisions with built-ins, stylistically distinguish user subs from built-ins, uniformity of sigils with other common user-defined items) are much more compelling to me than any of the reasons for not using them: "looks like Perl4" (big deal), "overrides prototypes" (don't use prototypes in most cases).
So I strongly disagree with Aristotle on that point.
(but my friends call me "Tye")