I changed my embouchure from the side to the center between the jr and sr year in high school ---- I ENDED UP SETTING OUT the senior year. Playing on the side, instead of the center, hurt my tone and flexibility ----- so for LONG TERM PLAYING considerations ---- I switched, and it was dreadfully hard, and took at least a FULL YEAR before I was as good as before I switched. IN MY CASE, I will argue that switching to the center of the lips was(is) the best choice for me, and in the end I am very very glad that I made such a switch. HOWEVER, it does cost in time -- and it is FRUSTRATING --- and in the end you have to decide what your future is with the horn. if you are just a hobby player -- then who cares,,,,,,,if you want range and flexibility, I will suggest going back to the center and sticking with it. ****note****** many people will argue that you are OK, on the side ---------BUT IN THE END IT IS YOUR CHOICE -- make the best choice.