Is SICP appropriate for an advanced high school CS course?
First, I love SICP. I took and later TA'd 6.001. Like many MIT grads, I tried to teach it where I became a professor, and, like most who attempted it, decided not to do so again.

The main reason it is rarely successful outside of MIT isn't the difference in student quality but the difference in the support the school can offer. If I remember correctly, at MIT, there were three lectures a week, two recitation sections, one tutorial section (approximately 4 students meeting for an hour with a graduate TA), and many staffed lab hours. A high school or small college cannot generally provide that level of support. Also, when taught outside MIT, it is usually as a junior-level course, and students still usually find it overwhelming. (An exception is UC Berkeley, which taught it successfully for many years at the freshman level.)

I am not saying a high school class could not succeed, just that it would be very difficult, and the amount of work required would be exceptional. 

It might also be hard to motivate students to work so hard on something so abstract, when they could be learning app development, computer games, or another more immediately rewarding topic with less effort.

In summary, I would advise against using SICP for a class at the high school level, although I do think it is possible to supervise an independent study with a sufficiently motivated and sophisticated individual or small group of students.