It was hit or miss for me. I'm Canadian and go to a Canadian Institution, but a lab is a lab, so I'll explain anyways.
Analytical chem took a lot of effort. At my school they are really strict with plagiarism (along with most schools). So we had a lab notebook we had to write everything in and weren't allowed to type anything out. We had lab preps where we had to write an introduction to the lab, list it's lab materials, and make a chart of all chemicals we were using along with their characteristics and safety information (had to research this, wasn't in the lab manual). We also had to write out the procedure in our own words (couldn't simply copy it from the manual), then had the write up on top of it. Each report came to about 20-25 pages written out (including the reference pages). We had to photocopy what we wrote in our lab books and then hand it in (that way there was no way of changing your answers). Had one every week. If you didn't do your lab prep before entering lab, you were kicked out. Had this same format for physical chemistry, biophysical chemistry, an upper level inorganic chemistry, and upper level organic chemistry's. Lab TA's were good for the most part, but some were dicks. I got an A on every single one of my reports, except for one where I got a C (in physical chem). So I asked the TA what was wrong, and he said my introduction was "boring." Really?! How the hell do you make physical chemistry not boring! lol.
But the one that really topped the cake was my organic chem I. So much to do in the three hours where if you mess up one step, you simply do not have time to start over, and have to explain in your write-up what happened (say goodbye to a good mark in this case lol). But the lab TA was such a jerk. Didn't help you with anything. Even sometimes I wanted to confirm a step because the lab manual was unclear, he would just say "what does the manual say?" in his arrogant voice. Or if I wanted to ask him a question, he would just say "what do you think?" then walk away. Not helpful at all. And he marked so incredibly difficult. We were only allowed to use one page written out to answer the report questions at the end. He said it will teach you to summarize things. So I would get my reports back (and only get B's) and he would say I didn't put enough detail in my answers, yet I filled the page with relevant information. I asked him how I could better summarize things, and his response was "print smaller." Worst experience of my life. The next semester for organic chem II I had a different TA. Got an A on every lab report and the lab exam. So basically, in my experience, a lab TA can make you or break you lol.
Sorry about the rant guys. Had to get that off my chest lol. I had many other labs, but they went smooth for the most part. Except maybe wine chemistry. Every report was a formal report, so they took forever.....and had a quiz every lab (kind of annoying, but not too hard overall). We got to make our own wine which was cool, but had to constantly come back to the lab on our own time to make sure our levels (such as volatile acidity) were as planned.