This was confusing, and could have been a little clearer in the reveal or at least a weekly update or something.

Part of the fun of the chase is figuring it out.

Rev like the Bungie that throws him in an area, give him a tool, and says "Figure it out".

Rev does not like the Bungie that gives him a road map with all the things in order he needs to do.

It's a huge reason why I'm so engrossed in Bloodborne- I forgot how good AAA gaming can be, when it's not trying to hold your hand!

I am not sure if you get better chances from the big chest on the higher difficulties or not.

The details on this part seem a little fuzzy at the moment. Part of me wants to think it is a better chance on higher difficulty, but so many of the people I've seen open it even on 28 have gotten exotics that I think the loot rarity is pretty much nightfall-level even there. I don't know how much better chance we could get without exotics being literally guaranteed (which is obviously not going to happen). See below for a thought on this...

Bosses can drop keys on 32 or higher.

I think that part's the key (c wat I did thar?) to the loot rarity. Since you need to run it at higher difficulty to get keys to drop in the first place, it sort of evens out.

And yeah, I know the Wolf packs would seem to throw a wrench in that idea. But, since they spawn relatively infrequently and you're not guaranteed a key from them (I have seriously only seen a single key drop in my time running them), I see that as Bungie's way of providing a less challenging but more time consuming route for people unwilling or unable to run the higher-tier PoE instances. And that's probably a good thing as long as they can keep the drop rates at a level where it's not MORE productive to run the easy way.

https://www.reddit.com/r/DestinyTheGame/comments/36nuqe/guide_prison_of_elders_treasute_chest_loot/crfo2d3

Lvl 32 is where you want to be to be getting the initial armor upgrades. With the exotic upgrades being exotic shards, anyone who can finish a 32 PoE should be able to get to 33 pretty quickly. Assuming that you don't need a specific rep level to buy the weekly pieces.

Reddit started a survey to see how likely you are to get an exotic from PoE, interestingly it looks like if there is a weekly lockout it's per account and not per character as only 1 person out of 341 reported they didn't get an exotic when using their first key, and the numbers go down significantly after that.

Here's the link if you want to look: http://www.reddit.com/r/DestinyTheGame/comments/36rdcm/survey_let_us_settle_the_treasure_chest/