It's been a while, I've been off in Treasure Goblin land trying to get Reaper of Souls into shape. I wanted to stop by to give everyone some insight into what we are doing with Magic Find. For those of you who have heard me talk on the topic before you are probably already aware that MF is something we haven't been thrilled with for quite a while. The idea of MF is great "GET ALL THE THINGS!" the reality of it however is incredibly problematic and leads to more negative effects than positive ones. Getting the reward rate of the game to a place we are happy with is a difficult tuning process and when we try to add MF into the equation is creates a bit of a dilemma, one that was already pointed out in the thread, how do you balance the game to feel good for someone with 0% MF vs someone with 300% MF. Ultimately the answer to that question is "You can't" as such we have been trying to phase MF out of the game as much as possible.
In addition to changing exactly how MF interacts with finding items we also have dramatically reduced it's existence throughout the game. Having strong characters already equates into finding more items, both by virtue of killing things faster and also by virtue of playing in higher difficulties, which still do have rewards associated with them. Because of all of this we decided to not only remove MF as an affix from gear but also change exactly how MF interacts with different item qualities. MF will apply 100% of its benefit to Blue items, 30% to Yellow items, and 10% to Legendary and Set items. This means someone with 300% MF will end up finding roughly 30% more Legendary and Set items than someone with 0%. The design intent is to make things like Topaz gems in helmets or the Nagel Ring an option without them actually being mandatory.
I hope this helps clear the air and as the expansion moves further and further into its development cycle I'll start climbing out of this portal more frequently to answer questions.
Rewards per difficulty are still something we are tuning. I'll remind everyone that the purpose of Beta and PTR cycles is for us to test things, that means you will see things that may or may not be final. In the case of difficulty settings being rewarding we are still discussing and making changes to that system so what exists isn't necessarily final. (Nor is anything until the game has actually shipped).
On the topic of people thinking MF is an awesome way to get loot! Well here's a different way to look at it, getting better gear is going to get you items faster. I would rather you get gear faster because you are more powerful and therefore murdering hordes of strong enemies faster, not because there is a stat that secretly is the most important thing in the game but doesn't feel good because you have to sacrifice real power for it.
As to whether the drop rates for legendary items are right, time and data will tell. We know they were absolutely too high in the previous beta so we brought them down considerably to something that was within the realm of sanity. Again as part of a beta testing cycle we took them down to a place that is probably too low, but to find the right resting place we have to find where the bounds are, we were far too high, if this beta cycle is "far too low" than we have dramatically narrowed in on our ability to find "just right".