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.
Another part I like about Dugi’s leveling guide is the ease of use. You’ll be given the guide in different forms so that you can find the one that fits you. For those that like to have a printed guide alongside them he provides you with a printable and image heavy version of the guide. A very powerful system Dugi uses is his in-game leveling addon that permits you to play without having to take your focus with the game itself. The addon adds a tiny window for your World of Warcraft game that tells you what area of the guide you’re at and how to proceed next.