I had a lot of the same complaints that you have. The guides made it really hard to see the overall big picture. This post along with this one pretty much single-handedly helped me to actually understand Ember so that the guides finally started to make a little more sense.
Ember sort of “clicked” with me a few days ago after spending a long time trying to wrap my head around it. However, Ember Data is kind of a whole other beast that I am slowly tackling. If you focus on understanding the object model and the overall big picture, you will get over a huge chunk of the initial learning curve. Then you can start diving more into Ember Data.
Some developers are working on revamping the guides, and with some input from newbies, I think that they will be great. You can also make your own suggestions in the guides repo. Just don’t throw in the towel yet - Ember has a lot to offer and once you grasp the fundamentals, the reward will probably exceed your initial frustrations.