Our Mists® leveling packages are tailored to get you to level 90 as soon as possible. Staying at level 85 will make you easily ganked by the new level 90's; likewise, if you're level 90, you can have fun ganking the lower level 85's! :-) By getting to level 90, you will have the upper hand on the economy through the auction house. Players will want to buy the new greens and profession mats that come out and being level 90, it will make it easier for you to farm these items. Additionally, you will be able to start gaining level 90 PvP conquest points for the new season 12 arena gear since the level restriction for Rated Battlegrounds and Arena is level 90.
At level 80, I skipped Cataclysm and went straight to Pandaria. Even as my warrior leveled up, and that heirloom axe increased in iLvl along with me, Dugi still ranked that iLvl 87 sword higher. I kept picking up new 2h weapons, and Dugi kept rejecting them in favor of that Wrath sword. That's when I noticed that all of these Pandaria weapon drops, even weapons 20 iLvls higher than the Wrath sword, had secondaries under 20. So even though Dugi Gear Advisor is showing that a new weapon would provide a DPS increase, it still prompts me to re-equip that Wrath sword every time I equip a new weapon. Meanwhile, I've kept the heirloom axe in my bags, assuming that at some point its stats would once again beat whatever I had equipped, but nope, it doesn't, according to Dugi.