Talent trees are the customizable feature that allows a warrior to flourish. When you gain new talents, especially ones that offer you new and iconic abilities, you’ll feel much stronger and it will add extra depth to your class. Within each class, spec helps distinguish between different players of that class. Even further, the talents you choose will help make you stand out from another player of the same class!
The vanilla WoW Horde leveling guide you see on this site was originally made back in 2006 by Joana (AKA Mancow, or FuriousPaul). The guides have been tweaked many times over the years to make things "faster". The leveling guides were made because of all the messages I got from people asking me how I was able to level up so quickly on new realms. I was first to level 60 on 7 different realms (3 with Mancow and 4 with Joana), even winning Blizzard's "First to Level 50" contest they held back in 2006.