I don't think Parry Gib is enough of a concern to alter entire talent specs over. I seem to recall my set up as having reckoning being the first thing I pulled points out of for something else, if only because its a diminuitive add-on to threat, but not much else. I think Parry Gib was a bit more important when you had 2 dozen village idiots smacking something from the front during the glory days. That's just my 2 cents though. Personally, I also find the magic number you need to be uncrittable a bit silly as well, not because avoiding critical hits isn't important, just that I see only a minor functional difference between 530 and 540. The real advantage to stacking defense is the huge increase in avoidance you see from miss, dodge and parry (and block). Not that you shouldn't be stacking Defense well past 540 anyway, I just don't see it as a magic cut off point.