Trimesters: Can We End the Experiment Now?

With a child at Skyline, I've now had nearly two years "trying out" the trimester system. I also have experience with block scheduling (the way Community High does it, which is essentially a semester system with every class three times a week) and with a traditional schedule (7 classes a day, every day). In Ann Arbor, currently, Skyline has a trimester system; Pioneer and Huron have a traditional semester schedule; and Community High has a semester-long block schedule.

It seems to me that we sometimes have a herd mentality in education. And so it goes in Washtenaw County, where a majority of high schools have switched over to the trimester--pushed, primarily, by the algebra problem and new state standards I describe here. (The state standards, by the way, are also proof of that herd mentality, as is high-stakes testing.)

So, I've tried the trimester, and here are its good points:
*There are only five classes in any day, so there is less homework due each day. [This is even better in an alternate-day block scheduling program, however, with homework only due every other day.]
*The length of the class is slightly longer, making it slightly more likely that teachers will use interactive teaching methods. [Some do, some don't.]
*If you don't like a class, it will be over in just a few short weeks.
*The schedule could be organized (at Skyline it is for science, but no other subjects) so that you essentially cover three years of a subject in two years.

Down sides:
*For languages, and for math if you are in a two-trimester level, you could go 8 months between levels. Yes, that's right--you could finish two trimesters of Spanish 1 in the middle of March, and not start Spanish 2 until the end of November the next year.
*The classes are slightly longer, but not all that much longer for project-based learning.
*Some subjects may move too quickly--for instance, AP classes are often set up with two trimesters of the class, and then a third trimester for review--which therefore takes up additional electives. So in fact, the same AP class that at Pioneer would take up 2 classes, ends up taking 3 at Skyline.
*It seems relatively likely that a student can end up with 5 academic classes in any given trimester, and no non-academic electives (i.e. art, personal fitness).
*Fitting in classes that really should go year-round--like orchestra--take up extra elective space. This is actually a disincentive to these classes. My child is not the only one who declined to sign up for band because it would take up three elective periods.
*It seems to me that it makes scheduling slightly more difficult, and it makes it slightly less likely that you won't have the same teacher for the next class in the sequence. (Of course, if you didn't like the teacher, that could be a good thing.)
*In the AAPS system, it makes it really difficult for students to dual enroll at Community High School because the hours do not match, and the terms do not match.

At the budget forum, I asked if the trimester system cost more (it seems like, with 15 classes available vs. 14 at the other schools, it should)--and the staff person at my table didn't know the answer. I still don't know the answer.

In any case, even if it doesn't cost more, it seems that if the schools had matching schedules, it would be possible to do more integrated/dual enrollment (once the schools are at their planned sizes). For instance, if a student wanted to take Chinese, and it is only offered at Skyline, maybe a Pioneer student could "dual enroll" and take afternoon classes at Skyline. Perhaps the only time for dual enrollment "switches" would be at lunchtime.

My first choice would be for all of the schools to be on the same block schedule that Community has. My second choice would be for all of the schools to be on a traditional semester system.
Can we end the experiment?