One disadvantage of the () = /regex/ syntax is that it does not work for continued (/g) matching.

It doesn't? Maybe I'm not understanding what you're getting at, but this works just how I'd expect:

  print "foo bar" =~ /(\w+)/,  "\n"; # prints "foo"
  print "foo bar" =~ /(\w+)/g, "\n"; # prints "foobar"
[download]