I've studied every single word of it. All 800 pages.
Some comments:
1. It's BIG. There's a LOT there. And it's just the tip of the iceburg; all just very brief summeries of doctrines far, far more extensive. It's not exactly apples to apples, but I have two Catechisms here at my desk. My Catholic one has 800 pages. My Lutheran one has 8.
2. What struck me is the almost entire lack of substantiation. Occasionally, there's a tiny foot note that gives us a Bible reference (almost never with the actual quote). I looked up and studies EVERY SINGLE ONE of them. At times, it seemed either entirely moot to the discussion or actually made the point in the Catechism problematic.
3. It's VERY articulate. OBVIOUSLY the language is very, very intentional and well thought out - to an extent very rarely seen in religion and even doctrinal books. LOTS of thought went into this. I always respected that, and still I use the book at LOT - I just like the clarity and precision of it.
4. I overwhelmingly agree with it. But here and there, something is said that just seems unsubstantiated. A dogmatic fact is made - perhaps remarkable - either with no attempt to document it as true, or if it does, that attempt is entirely inadequate to the point made. I - at times - found myself concluding that there's no reason to determine this is incorrect but also no reason even given to conclude it's correct. And those almost always tended to be issues where the CC departs from all other denominations, distinctives of the CC. Purgatory. Infalliblity of the Papacy. Transubstantiation. Immaculate Conception. Those issues.
5. CCC # 87 makes a foundational claim that should be solidly heard before one opens the Catechism (it should be in those early introductory points). Catholics are required to accept whatever the book says "with docility" as Jesus Himself speaking. This is on a par with Scripture. I think too often people read it as a sort of summery of what Catholics teach, they are to evaluate and consider it or perhaps use it as a reference book for Catholic theology. Wrong. They are to accept every word "with docility" as Jesus speaking. Read it as listening to Jesus. Accept every letter as such (and be a Catholic) or have the integrity to admit that you don't and leave.
It's one of the most referenced books in my library. I HIGHLY recommend it for all Christians. Not as infallibly correct, but as a very articulate and typically very excellent summery of Christian doctrine.