For strictly leveling your paragon level you might want to scratch out the idea of finding legendaries; you can always get magic find gear that still supports your character and adds a certain range of DPS damage per second.A reasonable DPS to tear through act 3 which is where you technically should be leveling. Is probably around the 30 000 + range.
Next up you want a socketed helmet with the highest tier possible of a ruby gem. The bigger the gem the more "bonus experience" you shall recieve. Next try your best to gear yourself with the Hellfire ring that you recieve for collecting all organs from the terror realms when you collect the three legendary keys off each act and open the realm of terror in act 1. You will have to fight two bosses at a time but the rewards are indeed quite rewarding. For more details I will do a post on how to open these portals. Note: Hellfire ring obtained from doing this quest will increase your bonus experience by a whopping 35% ( See post Diablo 3: Uber bosses.)
Where to level?
The most effective process of leveling is doing act 3. Here are the areas you would have to clear as quick and efficiently as possible. In order :
1. Core of arreat.
2. Tower of the damned.
3. Arreat crater level 2.
4. Keep Depths 2
(Take waypoint to keep depths 1 but skip it and walk right into depths 2)
5. Bridge to karisak
For bonus experience I recommend clearing Rakkis Crossing and Stonefort. If you are not fatigued from completing your 5 step run.
Difficulty?
No power level I find is most rewarding, but again if you can increase the level a couple notches and still be able to just run through monsters without having to pause for 10 seconds to kill an elite. Go for it indeed.
