Hey D94,
Just wondering, do you prefer smaller classes or larger classes?
Well small is preferred since you can actually engage with the tutor (I assume you are referring to tutorials). But given the nature of (mechanical) engineering, almost all classes will fill to at least 80% capacity, if not 100%.
Labs are a bit different though, but there are advantages for both small and large (which can be applied to tutorials as well). Smaller labs will allow you to have more attention from the demonstrator and potentially finish quicker. Larger labs will allow you to have the knowledge of your peers as well, and people generally work together to get the lab done as fast as possible. You will also most likely be with your friends so it's a good atmosphere.
It's also good in small classes to be able to build rapport with the tutor or lab demonstrator. You never know where they might end up, maybe in a huge company or whatever. One of my lab demonstrators was talking about how the company he works for, Red Bull Racing, was hiring undergrad interns.
Overall, I'm fairly indifferent to class size, but probably lean closer to smaller classes.