Addon packages are pre-loaded, pre-configured packages filled with multiple addons. The problem with that is that often times it is hard to configure them to your liking without messing something up or even making the package unusable. More often than not, the package is configured to a specific resolution and screensize, and looks terrible or has wonky errors if you dont have that size screen or resolution. Whats the solution to this problem? Just do it yourself. Its easy. Maybe you like a few specific addons in a package. Just download those and your free to do with them what you will. Dont like an addons once you get it? Toss it out, no worries for the rest of your addons. Take me for example, i used to use a specific UI package( whos name escapes me) for the longest time. I had loads of problems with it. If i changed the setting on one addon, others would change with it or stop working. It wouldnt get updated and when i updated individual addons they no longer worked with the rest of the package. And then, finally, I discovered that in order to make a UI that fit me and how I play, I had to be the one to make it!. Now I have a UI that I love, that shows me everything I need to know, and looks great at the same time. Addon packages dont work, they dont look nice, and they dont account for individuality. Dont use them.
If you want to see my UI, follow the link : My UI, 25m group layout