Every semester is around 17 credit hours. There is 1-2 major classes that have a heavy workload and require studying everyday. I probably study anywhere from 15-30 hours a week outside of class. This includes reviewing, assignments, group projects, practicing in the dry lab, etc. I also do optional part time internships during my academic semesters, so that takes up an additional 4 hrs a week (there are also observations you have to do for classes).
To answer your most recent questions, it's pretty much what I expected. Some days are very stressful, but it's not always like that. It's doable. Not much changed between my 1st and 2nd year. Some semesters and more difficult but I can't say that there's a trend.
The main difference between PT school and undergrad is that you have to retain everything. Your classes are very much interrelated and they are set up to build off one another. You can't cram, you have to work hard and review during your breaks because future classes will be very difficult if you don't have the background knowledge under your belt. Not to mention, you have to know it for boards anyway haha.
I think if you're reviewing material every week and keeping on top of things, this is not a big issue. If you cram, it will be. Condense information from each unit so you have a good reference to look back to later. I use every break to my advantage and review some of my old classes to keep everything fresh in my head.
Oh, and I can say that my work study classmates never complain. Your professors understand your schedule and workload and will be very flexible with you.
Hope that answers your questions