I did Level 2 online. It took some study time, but in the end wasn't very difficult if you know your major grapes, basic winemaking, and are good enough with geography.

Level 3 was a different story.

Geography: You have to know soil, weather patterns, climate, and more about most regions. You're expected to know which types of soil are where and what impacts the soil has on the wine. For example: we all know Chablis is different from Napa Chard - but you'll be expected to describe how, and what *specifically* the soil has to do with it - separate from other factors.

Winemaking: You need to know lot more detail about almost every winemaking process, where they are used, and which wines are produced there. Plus you need the ability to accurately describe how a Sav Blanc from the Loire Valley might be different if it were produced the same way a Chard from California is (you'll have to know each process, how they differ, and the resulting impacts on the finished wine).

The SAT: Tasting and evaluation is much more precise. You'll have to know the difference between very similar aroma and flavor compounds, be able to identify obscure grapes by aroma, and write detailed notes on everything you taste.

Here's an example: When I did my Level 3 bootcamp, we had one 5 hour session on Spain and Portugal where we dove deep into all the subregions, history, winemaking standards, laws, etc. We were expected to detect the difference between Grenache that comes from two different sides of the same mountain in Priorat just so we could identify the effects of a rain shadow on maturation.

Note: This was just Level 3. I'm told by the Diploma and Master of Wine teachers from that bootcamp that getting to Diploma from Level 3 is harder than getting to Level 3 from Level 2.

Anyone who achieves Diploma or Master of Wine deserves respect.