I think it's entirely a matter of personal taste. I also try
to avoid the ampersand whenever possible, using parenthesis after
its name (empty if there are no arguments) to make it clear
that it's a function call.
There is at least one case, though, in which the ampersand has
a very specific use: if you write "&func" (this is, with ampersand
and without parenthesis) the function will be called with the
contents of @_ as arguments. I don't know where this is documented;
I learned it from Conway's OO-perl book.
Other uses for the ampersand include de-referencing code
references.
--ZZamboni