I started out with PowerScore and let's just say that when I discovered 7Sage I was completely lost with the info. I had learned before. For LR/RC/LG I would recommend that you stick to 7Sage and pick up a copy of the LSAT Trainer and/or Manhattan.
Later later later! There is definitely a shift after PT65 and while it is subtle, you will be thrown a curve ball if you're not prepared by being exposed to the most modern tests.