Does Monster Power Affect the Quality of Drops?
Solution 1:
Enabling Monster Power in Inferno causes all monsters to be level 63. Since item affixes are generated based on monster level, this means that any item can now generate the best possible affixes. You also have the best chance of iLvl 63 items spawning, which have the best base stats. Without Monster Power, you wouldn't get that until Act 3.
Otherwise, no. Monster Power has no impact on item rarity beyond the magic find impact.
Solution 2:
Monster power gives you additional :
- Xp
- Magic find
- Gold find
- Bonus item (The chance to drop a bonus item in addition to magic find, in inferno)
From the d3 official blog: http://us.battle.net/d3/en/blog/7540457/
Starting at MP1, each level of Monster Power will increase monster damage and health by a scaling amount depending on difficulty. To reward your audacity, your hero will receive bonuses to experience, Magic Find, and Gold Find (which will stack above the 300% cap). For Normal, Nightmare, and Hell, the bonuses look like this:
In Inferno, in addition to increased experience, Magic Find, and Gold Find, whenever a monster dies and drops an item normally (whether it be gold, a potion, or a piece of gear), the monster also has a chance to drop an additional bonus item. The chance to drop a bonus item will scale up with each MP level as detailed in the table below.
Solution 3:
No. The only improvements from playing at a higher monster power is increased chance for magic/gold find, and a increased chance of a regular white monster dropping an additional item when killed.
Magic Find also does not improve the 'quality' of a weapon modifier (i.e. adds 1000 damage instead of adds 100 damage), but it does have an affect of the number of affixes on an item may have. The higher the MF%, the more likely it is for an item to have more affixes (i.e. 6 instead of 4).