Weekly chest should only reward you on the highest key you complete in time that week anyway. +10 as a cap was obscenely low for Season 3, so at least that's moving in the right direction finally.
...are the people over at Blizzard Removed ? I ask this seriously, I can't think any other explanation for the Bob buff only on low keys.
do we have a list for TR vales for chests in S4? and costs (ie how many weeks of 10 keys vs 15 keys for best az armor?
+12 is the new sweet spot that +10 had been hitting previously. Sadly we can't get to Mythic ilvl with it now that war/titanforging is gone but we can get to Heroic at least just from our weekly chests. It still doesn't do much to add value to raiding or obtaining raid gear.