Functionality is the heart of these guides, what you are really paying for. There are a lot of aspects I could look at with regards to functionality such as; questing path; quest progression; addon user interface; bugs; performance and many more. All that we are concerned with are questing path (speed) & user interface. All the other aspects aren’t worth comparing as both wow guides are light in terms of system usage, both have very few bugs, and both update your quest progress in real time.
Dugi’s Guide has released their Cataclysm bonus which is an in game talent advisor. Finally and actual bonus worth talking about; or so I thought. Once on the inside of Dugi’s Guide members area the truth was revealed. The talent advisor bonus is just the 3rd party addon “Talenteds”! Using TomTom add on for navigation is already a large negative in my books, now offering a free addons as a bonus. Dugi, Dugi, Dugi.. – not cool. I’m tempted to take another point away from Dugi but that would be my personal opinion.
Pick a simple goal or idea for your AddOn. It's often a good idea to just make an AddOn that only opens a window or prints a message to get started, especially when everything is new for you. After that works the way it should, and you have learned everything necessary to make an AddOn work at all, you can move on to adding one piece at a time toward your goals. Writting software in general is often a never ending process because you can always think of something new to add or improve.