I would keep :) There are 5IV'd ones around thought, but personally I kept a 28/0/31/30/31/31 so yours is probably better if it has 29 spDef.I got a 31/x/31/31/27,29/31 timid latias on my second SR in-game (AS). I'm hoping keeping it was the correct choice? I confirmed the 31s with hidden power (dark).