I just finished the level one ISG course at SAIT (in January). It was great, all the basic regions and varietals were covered.
What I found was the learning environment was quite formal, desks in a class room all facing a screen. Most of the content was taught through powerpoint. We also had tastings at each class (6-7), which was the best part! I prefer a more interactive and informal learning environment (especially when it's just for personal interest, I'm not seeking a career in the wine industry).
I am looking at taking the WSET intermediate course next as I've heard that it's informal. As a side note WSET is also more internationally recognized than ISG (which is mainly known in Canada).
I took the very expensive every Monday for several months class about 10 years ago, it was fabulous - very informative and totally worth it, certification at the end if you pass, but quite a big commitment unless you're independent or in the industry. I haven't taken any shorter courses (not sure what is offered now).
Mrs Scary and I took a couple of the WSET courses and found them to be very good. We didn't go further because we're not in the industry, but did find that we learned a lot. The problem is that you have to keep drinking great wines to keep your palate strong. Oh yeah, and another problem is that you never want to drink plonk again. It has made us into value hunters.