Questing addons in WOW
OK, heres the Heads-Up. I'm a WoTLK player (Patch 3.3.5a), and I swear by Carbonite too.
Quest helper is mostly just a tiny little arrow pointing you in the direction that your quest target is in, but doesn't take into account that there may be multiple zones where you can finish your quest.
Carbonite , on the other hand, Tracks your quests on a interactive minimap, Zones out all the locations in color , points you in the right direction, and even warns you when enemy players are abound. It also contains a list of quests that needs to be completed in a handy little box.
downside is, Playing the game without either addons named above is the best way to learn and to use your quest log and Map.
so this is really a question of "What is your flavour?"