Comparison using <> operators should be documented. Between two objects, at least in PHP5.3, the comparison operation stops and returns at the first unequal property found.
<?php
$o1 = new stdClass();
$o1->prop1 = 'c';
$o1->prop2 = 25;
$o1->prop3 = 201;
$o1->prop4 = 1000;
$o2 = new stdClass();
$o2->prop1 = 'c';
$o2->prop2 = 25;
$o2->prop3 = 200;
$o2->prop4 = 9999;
echo (int)($o1 < $o2); // 0
echo (int)($o1 > $o2); // 1
$o1->prop3 = 200;
echo (int)($o1 < $o2); // 1
echo (int)($o1 > $o2); // 0
?>