I would put a 100% military spec Kifaru pack up against McHale any day, both brands are excellent! There is a reason however, that the US Armed Forces use Kifaru :)
The KU packs are insanely well made, and deceptively strong (with a very reinforced bottom panel by the way).
Check 'em out a little closer, you'll see raving reviews, a very loyal following, 80-85% resale value, and I would bet McHale's go for as much or more than $530 bucks once you customize and order.
In any case, McHale's packs are things of beauty, and are just as capable I am sure, I just don't have one personally to compare to the Kifaru.