No good single resource for conceptual physics exists. Sure, the Hewitt text ain't horrible, but try putting yourself in the mind of a 14-year-old who is utterly new to physics, and to academic life as well. All Hewitt's clever little asides do nothing but distract; his vocabulary (even in "The High School Physics Program") is more suited to seasoned law clerks than to general-track freshmen.
Nevertheless, I have to teach freshmen rigorous conceptual physics. As we've moved into kinematics, I've ditched the textbook entirely in favor of a typed sheet of "information to memorize." Take a look at the sheet in this link:
While this two-page sheet covered about three weeks of class, I handed it out in steps. During the first week, I gave them only the eight facts listed under "motion diagrams" and "position-time graphs." Those eight facts were plenty to do serious experimental work with spark timers and motion detectors, and to answer any conceptual question about position-time graphs, even up to the low AP level.
Then in the second week, I redistributed the sheet, adding the rest of the first page including "velocity-time graphs" and "questions to answer when describing motion."
Finally, I passed out the back page, which stated four facts relating to acceleration, and the three relevant equations for distance traveled.*
* One for constant speed, two for speeding up from or slowing down to a stop.
This piecemeal approach mitigated one of my major issues with textbooks: too much information. Rather than asking students to wade through pages of densely-paragraphed hard copy to find the important facts -- if they even know which facts are important -- I just wrote the important information by itself.
I'm sure some idealists, education professors, and textbook publishers will argue that my approach substitutes dry facts for rich context. Yes, yes it does. It is incumbent upon me to provide interesting and useful context through class activities, experiments, demonstrations. That's what I'm paid for. If merely reading a perfectly-written textbook could possibly be sufficient for most students to understand physics, then all of us physics teachers should find another job; we'd be useless.
Since my school expects me and my students to show up each day for class, I'm going to simplify the background reading to its bare-bones form. Then out-of-class time can be used to practice problem solving; in-class time is used to ensure that the out-of-class work was done carefully, and to provide in living color the active physical context that not even the best-written textbook can hint at.