Hi Dugi,
I use and paid for your guides, and donated to Carbonite as well. Love both these add-ons and can't highly recommend them enough. Dugi's mob targeting and the quest navigation features are a fantastic time saver that make WoW a lot more enjoyable. And your narratives for the quests are better than slogging through any quest narrative to try and decipher what you're supposed to do...
Like others here, I also find Carbonite a *Must Have* for the Google Maps-like feature, and warehouse / inventory tracking, and finally for the "GoTo Map Coordinates" feature. Carbonite is a nice to have for the player tracking, and quest status broadcasting to party. Finally, Carbonite helps me with Gathering by offering node location importing for my gathering professions and also allows me to place notes on the map. Like, "* - Good place to farm Cloth." So Carbonite is different enough from Dugi's guides, and has some irreplaceable features. If you're looking to develop these into your guides, hey, I already said I pay for your products, so there you go
-happy customer