I've never been in a similar situation to any of you. My high school has never taught lessons that were covered the year before, except in the case of a few teachers who spent a day reviewing an old topic before immediately expanding upon it. Every year I've been in a public high school, the classes I took were challenging, and we covered tons of new material.
Then again, I opted to take the IB Diploma Programme, and I filled my schedule with IB and AP courses. Has it been worth it so far? Absolutely.