Deciding when to move on is a very personal decision and is very different for everybody. Honestly ask yourself these questions: Are you confident every time you fly? Can you make a good crosswind landing precisely using the rudder? Have you been practicing any mild aerobatics? Do you still get disoriented? Can you consistently tune an engine properly and not worry about it quitting mid-flight? If you are still content with the trainer then I would still fly it. The more time you put on the trainer the better the chances for success when you decide to move up. If you feel you're ready just take it easy with your new plane for a little bit and get to know it very well. I usually spend a couple months of flying with a new model before I feel I am adequately acquainted with itl. It easily takes longer to get is set up just exactly how I want it.