I’m moving on from this thread, however, you forgot (at a minimum) the opportunity cost on $134,000 down payment. At 4% interest this is an extra $446 monthly on top of your $3980. (an extra 10% a month is more than just a little difference, too…isn’t that amount enough to sink most ARM holders?)
Lastly…the home you linked to isn’t even in 4S Ranch. It appears to be in Patina…much, much nicer than 4S Ranch, likely with an ocean view and beautiful upgrades.