Definitely take the class. That said, the only way to improve is to keep practicing. I do a lot of ruler work using the Westalee templates and they are wonderful, but like all Fmq there is a learning curve. I guess the question is what is it that you would like to improve in your quilting? If you are looking to do smooth curves and lines without wobbles, the the rulers will be a good choice. If you want to be able to spend less time marking your quilts, then the rulers will be helpful for that as well.
Rob