I'm signed up for Leah Day's Free Motion Fillers but I'm still at the making the quilt top stage so it is hard to say. I do like Leah and have already picked up a tip or two on making the quilt sandwich from her class. You can go to her website and watch her videos to see if her teaching style suits you. I really like her approach. There are several advantages to the Craftsy class over watching YouTube or going to Leah's site.
First, you can ask questions and get answers.
Second, you can do the 30 second repeat so if you didn't quite 'get' something a simple click gets you right back. Much easier than trying to do that on a YouTube video.
Third, you can make notes and mark spots in the class so you can return.
And last, but not least, you can post your photos and get feedback on your progress.
I think it is well worth the money but I would also suggest you go to Craftsy and sign up for one of their free classes - like BOM. This will get you on the mailing list and you will received notices for sales on the classes. They have sales fairly often and you can save a little money that way.
Here is a link to Leah's website where her free videos are posted by difficulty level and it will give you a chance to see her teaching style.
http://www.daystyledesigns.com/365difficultymain.htm