I RUN BOTH LRP SPHERE TC AND A GTB. THE SPHERE NOW HANDLES MY 3.5 WITH OUT THERMAL PROBLEMS LIKE THE GTB DID. MY GTB HANDLES MY 10.5 AND MY 13.5 WITH EASE, (HOWEVER I AM SWITCHING TO A LRP FOR THAT ONE AS WELL) THE GTB WORKS GREAT WITH THE HIGHER MOTORS (IE 10.5,13.5) BUT I DID NOT LIKE IT WITH MY 3.5. IT IS A GREAT SPEEDO I JUST LIKE THE LRP BETTER AND EASE OF PROGRAMMING.