A lot of people say that CS 33 is easier than CS 32. I definitely did not find that to be the case. Where CS 32 is practical application of quick to learn concepts, CS 33 is dense in theory.
Note: This review is of Spring 2020 which was a special remote learning quarter due to the pandemic. Some things may be different in person.

TLDR; if you have to take this class, take it with Professor Reinman.

Instruction: Professor Reinman, as noted by many reviews, uses the flipped-classroom approach. You'll have anywhere from a 30 to 70 minute video to watch before each lecture. If you understand that, you get context for the class and can ask doubts which the professor answers quite meticulously. While it's officially called flipped classroom, it's more like saying that the professor gave you the slides of what he's going to go over in the class beforehand... attached with an audio file. I personally found it easier to keep engaged in the class since the material is so dense I'd have to go over it multiple times.

Labs: You will most likely have data lab (binary manipulation of integers), bomb lab (finding answers to a "bomb" puzzle using GNU debugger and interpreting x86 assembly), attack lab (manipulating your input in a way that circumvents design of a C program), and parallel lab (given some C code, you have to optimize it using optimization techniques and parallel programming). All of the last three labs have extra credit, even if the professor doesn't say so initially. Make sure that you grab all of that; it might end up being very handy. In terms of difficulty, Data lab > bomblab > attack lab > parallel lab (personally that's what I think. but most would agree that data lab was the hardest).

Keep in mind if the professor opens up some assembly code in the first class and talks about it like you should know all of it somehow beforehand, it would be nice to know that he'll teach everything about that and there's no need to worry.

Midterm and Final: There is just one midterm for the course, so make sure you do that well. Due to the special circumstances, I was able to opt out of the final, so I can not say much about that. But the midterm was to the point, however a little tricky here and there. Make sure you have a good understanding of the concepts; ask as many doubts as you have. If you do the labs yourself, you'll be fine for midterm. Would definitely recommend the LA worksheets as well. (Thank you LAs for your help).

The course is well constructed. It may look useless at first, specially coming from something like CS 32, but will end up changing the way you code for optimizations that don't involve algorithmic changes. Professor Reinman is great; he maintains a cheery attitude and genuinely tries his best to help everyone succeed.

Note: this review was made in Spring 2020, a special year with a lot of discerning events. I did not take the CS33 final and cannot comment on it. For that part of the class, discard my review.

Glenn is great; the wave of reviews should comfort you. It's also simple to do well in his class, if you are diligent and work properly.

This is the very class that, if you attend lectures, start your work early, read your assignments properly, and check what you turn in thoroughly, you will GET AN A. People say this for a lot of classes but it's TRUE for Glenn.

Glenn is also very understanding and reasonable. Just super cool in general.

I got a 0 on the Parallel lab, but still got an A- because of extra credit from before. Yes - take extra credit on labs, in case you do screw up big-time elsewhere. Extra credit for the Bomb lab is especially easy (Attack lab, maybe not so much).

Also, please read lab specs carefully... that's why I got a 0, haha.

This is also the class where CS becomes *partly* less interesting than before. If you find it hard to just be a diligent student and pay attention, and you don't have any crazy environment, then it's not that CS is wrong for you - it's that you need to improve as a student. CS33 with Glenn is very accomodating for students, and it also has very important topics that you must digest.

The content of this class is very useful for understanding the computer system as a whole. But who the heck said that this is easier than CS 32...I even think the workload is higher because of the flipped mode (pre-lec recordings + lectures). Rienman is a nice dude but to be honest, he didn't explain the content very well.

LONG LIVE REINMAN!!!!!!!!!
GOD BLESS THIS MAN

CS系的Haofei Fan！我就问还有谁？？？ 拉面人万岁！！！

I'll just put it this way: when you think other classes are hells this one is heaven! It is literally that big of a difference. Holly Reinman!

You got this class, you got the best deal ever.

While I didn't find Reinman to be the most engaging lecturer ever (I guess its because everyone CS lecturer seems a little dull after Carey's class), I can't deny the fact that he did an outstanding job teaching the class. He made me feel very comfortable in his class and answered all the questions everybody had.
He also appears to be willing to increase the weight of your final to make up for poor midterms if you show a demonstrable improvement on the final. He does use a flipped-classroom approach and also has 4 hours of live lecture every week, which means there is a lot of lecture to attend. However, I found most of this to be very useful to help understanding course material. It is very evidence that Reinman wants students to do as well as possible in his class and to master the material.
The midterm was very reasonable though the final was quite difficult in my opinion.
Overall I definitely recommend this class. Reinman is an outstanding professor and definitely deserves all the praise he has received.

would take rhinoman over nachenberg in a 1v1 arm wrestling match to the death. 10/10 could not give the man higher praise.

I scored an A in CS 31 and 32, yet a B- in this class. Here's why.
Reinman uses the backwards-classroom approach, which you've probably read about (watch a video before each lecture, and the lecture discussion is about the video).

First of all, the class was at 8 AM on Monday and Wednesday, and oftentimes I simply did not have the time to watch the video in the time frame he gave us (he would upload it roughly a day before the class).

What made this class extremely difficult for me was the lack of clarity in what Reinman was saying in his lecture videos. He used vocabulary loosely and did not explain things in the way that the computer understands them. Smallberg, on the other hand, was a master at introducing concepts in a way that conceptually makes sense with the computer.

Thirdly, most of the content (which is a BUTTLOAD of work) is not even on the exam!

It was really frustrating to see that I put in a lot of hard work and have the CS intelligence to do well, yet failed in my standards (B-). I honestly believe this is the fault of the professor though.

NOTE: If you decide to take this class, FOCUS ON THE LABS!! I made the mistake of studying for the final by making sure I understood and memorized every detail of the videos instead of practicing the labs.

No idea about everything he said

His not as good as Carey, but still a very nice tracher