Here's a link: High School math failing to make the college grade ... hoping this link stays good for a while.

Basically, even for your smart guys, if you go too fast, they don't get a good foundation. That godawful correlation that has been translated to cause/effect hurts. The correlation: students who've taken higher level math courses do better in college. The fallacious conclusion: we should make students take higher level math courses, sooner.
If you're not ready for Algebra II, you're not ready for Algebra II.
Folks, I was in the fastest track in math... but our wonderful crusty wrestling coach teacher split us into groups and each group had to do oral presentations of about four major concepts we confronted in each of the two years I took math from him. That's right, we'd basically take a *week* and hear the same stuff FOUR TIMES. The idea of "here's the formula, memorize it so you can make our test scores look good" was not entertained. We *derived* all that trig stuff... and then learned the short cuts. Mental Perspiration happened. I can tell you that it would not have been my preference, but I could not do what I do today if Doc McNelis hadn't forced us to comprehend that stuff (or at least established that as the status quo).