Number of loot chests does differ between different rankings for Quest rewards.
Bronze 1 chest
Silver 2 chests
Diamond 7 chests
Champion 10 chests
If you decide to buy quest potions, which are 7500dec for 10 charges, this will give you an extra 5 chests for your quest completions. Each charge equals one quest.
Curious...
I was bronze yesterday, daily quest gave 1 chest. (good)
I was bronze today, did the daily quest but didn't open, leveled to silver, then opened the daily quest... still gave 1 chest. (odd)
Do you need to be silver before completing the quests to qualify for the 2?
Or does the daily snapshot record your level once a day for daily quest chest purposes?