Now that the machine has been around a while, what modifications are recommended for this machine? Are there any that are considered “must do”? I have read a little about problems with the cam locks. Is there a fix for that yet? I have also read about people changing out the stock shaft a lot. Is there a style or brand that is preferred? What are the advantages to a replacement shaft assembly? I am still on the sidelines as far as buying one but I am trying to do my research and get all the info up front. Thanks in advance for all replies.