I had a zealot sitting around from before I even started on Bnet, and decided to start stuffing him full of gear like vamp gaze and HoZ and see what happens. I noticed, even in the level 50s his defense was nearing and then surpassing that magic "10,000" defense. I always hear that number as the number to do or not at all. But I realized I don't know crap about defense as I've never really gone that route before. Is there a number to stop at? Is it worth it to max HS and defiance, or even get a defiance merc? Are there diminishing returns?