You're testing compile time. First scripts loads Moose and tons of its dependencies. Try to write some more realistic tests. Here's something to start:

use 5.010;
use strict;
use warnings;

{

    package M1;
    use Moose;

    has x => ( is => 'rw' );
}

{

    package M2;
    use Moose;

    has x => ( is => 'rw' );
    no Moose;
    __PACKAGE__->meta->make_immutable;
}

{

    package M3;
    use Moose;

    has x => ( is => 'rw', isa => 'Int' );
    no Moose;
    __PACKAGE__->meta->make_immutable;
}

{

    package NM;

    sub new {
        my $class = shift;
        return bless {@_}, $class;
    }

    sub x {
        my $self = shift;
        $self->{x} = shift if @_;
        $self->{x};
    }
}

use Benchmark qw( cmpthese );

cmpthese - 5,
  {
    "Moose mutable"         => sub { M1->new( x => 1 ) },
    "Moose immutable"       => sub { M2->new( x => 1 ) },
    "Moose with type check" => sub { M3->new( x => 1 ) },
    "No Moose"              => sub { NM->new( x => 1 ) },
  };
[download]

Generally, if you're using Moose, code performance will decrease, but your performance and code quality will increase (though it depends of course).