I suppose I should chime in, seeing as I graduated from high school about nine months ago.
I took a few AP classes. Not 7 or 10 like many geniuses in my school did, but a respectable amount for things that would actually help and/or I wanted to get out of the way for college. Combine the APs with a lot of difficult non-AP courses and the homework load was kind of ridiculous. In my high school, it was not uncommon for juniors and seniors to be given 7+ hours of homework every night. My high school was in an area where AP exams, SAT scores and getting into that prestigious university was everything to the teachers, so they slammed it down our throats with tons of homework and other such things. The annoying thing about the homework was that it was rarely actually useful and usually just busy work; work for work's sake. And now after I've graduated I already find my brain quickly forgetting everything I learned in high school that was unnecessary, which ended up being a lot.
Other than the whole stupid amounts of coursework, both in the classroom and out, there were other stupid things going on as well.
The most obvious one was the classic high school drama which is so rampant in every high school. People were constantly gossiping about each other, spreading false rumors, twisting true ones, getting together and breaking up, dragging friends into their relationship roller coasters, not getting along with people who hung out with them, and so on. It was pretty ridiculous in my school, but I was fortunate enough to not be involved in just about all of it. The only time I did was when prom season came and my closest friends and I deliberated who we would ask. Early plans would fall through as potential dates accepted other people's offers or got together with someone, and I ended up having to ask two people, even though both said yes. It was a ridiculous process, but I did end up getting a date and going to prom, which ended up being a fantastically fun trip, dinner, and after-prom bowling party, with a very underwhelming actual prom dance. Nothing ever developed between my date and I, but it was still an enjoyable experience.
Besides this, I never had a girlfriend until the summer after I had graduated (and that fell through pretty quickly), I didn't have a terribly large group of friends (but not that small either, to be fair), several of my teachers and the ridiculous amounts of coursework nearly drove me insane, and I constantly felt like I was in hot water due to my grades being on the brink of being unsatisfactory for my dad.
HOWEVER...
I loved it.
Unlike most people, I did realize going into it that it would be gone extremely fast and if I didn't savor it I would regret it, especially after my freshman year World Civilizations teacher said "don't blink, you'll be a senior." He was right, but I did savor the years, and walking out of the graduation ceremony I had no regrets. I pretty much took part in every good experience high school had to offer. I had an awesome group of friends who were always there to hang out and do stupid things that you can never do again after high school and I gained a vast archive of memories that I hope to never forget. Right now I'm in college, and while it is admittedly extremely superior to high school in nearly every way (any high schoolers in this thread take note: college is awesome), I still miss high school and wish I could go back.
So my advise to anyone actually still in high school is: cherish the good things, forget about the bad things as they won't matter in a couple of years, do as many stupid things (within reason) with your friends as possible, and make your goal to graduate not still wanting to do anything you can do in high school. Then it will seem like the best four years of your life.
TL;DR: high school is awesome, but only if you realize it.