<?php

function test( $re, $text, $iters ) {
    $t1 = microtime( true );
    for ( $i=0; $i<$iters; $i++ ) {
        $res = preg_match( $re, $text );
    };
    $t2 = microtime( true );
    echo ($t2-$t1).PHP_EOL;
};

$re1 = '~"([^"\\\\]|\\\\.)*"~';
$re2 = '~"[^"\\\\]*(\\\\.[^"\\\\]*)*"~';
$text = "\"some text here\""; 
$iters = 500000;

test( $re1, $text, $iters ); // => ~0.45
test( $re2, $text, $iters ); // => ~0.22