Went in with CAD experience so I can't speak for how well Gao teaches it, but overall I'd say that he's a fair professor. Homework and a lab every week, plus a final project, but no exams. Most of the class is learning drawing conventions, working in SolidWorks, making models, and turning the models into drawings. Depending on your TA, prepare to have your homework put under a microscope though.
One word of warning, the final project is relatively simple but is accompanied by a tedious report. If you can, pick people who you know won't slack off... Don't ask me how I know.

This class is easy and all but it's mildly annoying. Lectures are clear but they are drawn out and remedial. Homework is mostly busy work where they go for quantity over quality of questions. It'll ask for like 15 part drawings or 40 questions asking you to look up values from a table. It's nice to have a final project instead of exams, but the report is way longer than it needs to be. It's cool that we're 3D printing. I'd recommend attending nothing and just looking at lecture slides to do all the assignments. Start the project as early as you can, but don't be worried by his constant emails. You can start in week 9 or 10 and be fine, just be aware that it will take multiple prints to get everything to work how you want.

Class was pretty easy. Weekly assignments and homework were time consuming but they graded very leniently. Final project was a nightmare because it was so much work. If you had any CAD experience from any engineering clubs the labs should we easy.

Prof Gao was great -- super, super helpful and very understanding. The class taught SolidWorks extremely well -- which is very helpful as a MechE student if you're looking for research or an internship. The group project was a nightmare (mostly because of my group), but they grade everything very nicely so it was not a lot of stress. The class was a lot of work -- there were a lot of assignments that took a lot of time, but it's hard to teach a whole program in 10 weeks, so given that Prof Gao did a great job.

If you are a part of an engineering club that uses CAD, you will probably be a little bored in this class. If you are not and have no CAD experience, it will probably be a bit confusing at first. This class was a bit disorganized and the professor was hard to reach. I personally relied on the TA to clarify things, but it seemed like the TA and the Professor didn't communicate much. That being said, as long as you do your work, which can be a lot at times, you will do well in this class.

Class felt super disorganized, I often had very little idea on exactly what the expectations were for each assignment. I also generally just felt a lack of clear communication between the professor and TA. The grading is relatively lenient, though, so that makes up for not knowing what is even expected. I would also come into this class with a group prepared for the final project, because if you don't have one they don't even prompt you to start communicating with your group, and there isn't any class time dedicated to that, you just have to figure it out.

Take Gao! He is a very engaging and straightforward professor. However be warned--this class is very work heavy. We had lecture exercises, homework, and lab due pretty much every week along with the final project. The homework definitely took a long time because you had to do a lot of drawing and googling--not hard but just very tedious and took many hours. The labs were very helpful but also pretty time-consuming. The finals project took the most time by far--our report ended up being almost 100 pages. But overall, I learned a lot about Solidworks and the basics of engineering design. Gao explained things very well and taught a lot of concepts. As long as you do your work, you should get a good grade.