I strongly advise everyone to avoid the classes. Considering your score range and how little youve practiced I would tell you it will be a complete waste of your time and might even hurt your score, at least initially.If you read some of my other posts you will see the many reasons why I feel that courses are a waste of time but the number one reason and the one that would overwhelmingly apply to someone scoring in the 170s is this...You will waste a lot of your valuable study time sitting through instruction on the weaknesses of others in spite of them being your strengths. A good tutor will focus on your weaknesses.So if you feel like you need help get the books that are recommended by most of the elites here and if you dont stabilize your score in a place you are happy with then get a tutor.good luck
The first line of this guys advice makes me suggest disregard every word.