Do you feel like you end up with as clear of a mental model reviewing it as you do if you wrote it?

I'm still trying to figure out the answer to that question for myself. Maybe the answer is, "Probably not, and it probably doesn't matter" but I'm still trying to figure out what kind of downstream effects that may have later on my judgment.

Yes, of course I do. It's rote stuff. To the balance of time we're accruing to me dealing with generated code, add "stripping off all the comments", "fixing variable names to be like I like them", etc. My fingerprints are still all over everything. And it's still radically faster than doing this all by hand.

Mental expenditure on programming is also not linear through a task; it takes much more energy to get started than to do the back half. Ever stared at an empty function for a minute trying to come up with the right variable name, or choosing which value to compute first? LLMs are geniuses at just getting things started.