When I went to high school we originally had the tradition schedule, 7 class days. Then we went to a half block/half traditional schedule where 4 classes were 90 min and were A/B days, and another 3 were 50 min. That was weird.
As a student I much prefer 50 min classes. It's hard for me to keep focused for longer than 30 min. As a teacher I like 90 min classes. I feel like I can get so much more done, and since I know 90 min is a long time I plan lots of stuff, change activities frequently, move around, etc. I never spend longer than 20 minutes on one activity.
I have taught on both. We started with a rotating A/B block schedule with roughly 90 minute periods. We then transitioned to a traditional schedule with 45 minute periods.
For my content area (history) I felt that the traditional schedule was MUCH better. The kids simply didn't have the attention span for the block period, and I found myself covering far less content. Some classes would only meet twice a week, so I would get 180 minutes with those kids. Under the traditional, I get 225 minutes with ALL kids. And better still, that time is spread out over the week so their attention is better, and the content is repeated, thus helping with retention.
I am a HUGE fan of the traditional schedule, and would never like to go back to the block. Granted, the 90 minute prep period was nice, but the traditional schedule is better for the kids.
You get more time each period with the students. I feel like we just get going now and then it's time to leave.
With some schedules, the kids have fewer classes so they keep up better and do better. That makes our lives easier.
I was able to do more projects.
The school I work at (sub) has block scheduling. They call it A day and B day. On A day they have four classes and on B day the fourth class is a homeroom/study time. The teachers have one prep every day. This schedule works really well. During the homeroom period, the students are to silent read or silent work for the first 30 minutes, then they can go to other classrooms to get help from teachers on their assignments. Very few students have to do homework at home and have great access to help with this schedule. It can feel very long, but I think once you get used to it, it is actually really nice because you have lots more time for a really good lesson. Also, the homeroom class is useful to do activities like pep rallies, school photos, assemblies, etc... without losing instructional time.
For us, our periods are only 43 minutes so we would gain a few hours if we switched to a block schedule. However, even if we didn't, I find that the block schedule wastes less time. You don't spend as much time settling down, getting started, doing housekeeping tasks, etc...
Our school does a mix of block and regular. For example, CP English 12 is an all year course, 43 minutes per day. However, Algebra II is a semester course, 89 minutes per day. I know our science teachers would love to have block scheduling so they could do longer labs.
As a protech teacher block schedules are THE BEST thing that we get. Frankly it adds up to 20 minutes to class because the 10 minute set up and 10 minute breakdown only happen once every 92 minutes instead of once every 50.
We have block here. I like it. If you have a class that you absolutley can't stand, you know you only have to deal with them every other day. I get much more covered in 90 minutes. I teach 3 classes a day, and get a prep every other day, and a duty every other day. My duty is a study hall- so it's an extra planning for me.
I've also taught 4X4. As an arts teacher, it was terrible. Electives were staggered, so sometimes, it was difficult for kids to enroll in classes. Also, I spent more money on supplies--I had to buy them twice a year instead of once. Field trips suck too, one group gets to go, but if it's not available the second or first semester, they can't. I also feel I don't get to know my students as well--I finally get really comfortable with them, and they're gone.
I've also taught traditional, which I didn't mind, the periods were too short though.
College is every other day, 2 to 3 hour classes, so I think block is more realistic for what they need to be prepared for.