I think that as others menitoned, it is only the people with problems who tend to post as the others are too busy sewing! One thing to do is to look at the kinds of problems they are having. If most of them tend to be user errors and you are pretty good at figuring things out, then go for it!
Another option might be to get one that a good friend has so that you have someone really handy to help you.
I've not taken machine specific classes, but have learned by trial and error and by having someone either nearby or online to answer my questions.