I dislike the idiom because it promotes ambiguous code. The author of  $obj->new(); hides something that the author of  (ref $obj)->new(); tells you.

Often it makes no real difference and the noise is about who is being forced to write code to accomodate someone else. I try to be more cooperative.

Usually I would write your new more like this.

sub new {
    my $class = shift( @_);
    croak "Bad class parameter" 
        if not defined $class or ref $class;
    bless [@_], $class;
}
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Which gives a message like:

Bad class parameter at file.pl line 100

What is it that you find fine about the idiom?