I've just finished watching this class and thought I'd post a review of sorts:
This is a watchable but basic class, best suited to those who are quite new to coverstitching. I've had my machine two years and had worked out how to hem decently and flatten seams and neckbands so I was hoping to have my knowledge expanded. I did pick up one or two useful tips and saw them use a couple of attachments (which I'm unlikely to buy). But overall I was familiar with the techniques and information that they covered so I probably won't watch it again. I already have Johanna Lundstrom's ebook Mastering the Coverstitch Machine (also in paperback) which I've really only dipped into for specific issues, so my next job is to read that through properly. That has so much information I hardly know where to begin!
On the plus side the class only cost me £10 (and the Stitch Sisters (whose Youtube vlogs I watched for a while last year) do a decent job of presenting the basics clearly and pleasantly. I think if you're someone whose machine makes you slightly nervous these two will definitely help you feel more confident around coverstitching. If like me you're not a beginner and were hoping to learn some advanced tips and techniques you might be better looking elsewhere.
Summary: decent class for coverstitch basics.