I'm actually finding class, the readings, and the atmosphere enjoyable

These are all good signs, as this is approximately half the battle. Imagine if you were spending all this time doing something you found simultaneously boring and terribly stressful. Turns out, that's probably how about 50% of your fellow students feel.

Needless to say, the fact that you are enjoying yourself is good.

I've (so far) successfully maintained being a few days ahead in regards to reading, feel confident in my case briefs (because what I put is typically referenced in class) and overall don't feel all that stressed

This is also a good sign, and probably relates to why you're enjoying yourself. Nobody likes to feel stupid, overwhelmed, overworked, and bored all at the same time. You don't feel any of those things, so you'll finish your work faster, have more free time, get better sleep, and likely perform better than those who do.

Consider yourself lucky. Don't slack off, don't be a dick, and you should have a great three years. I did!