ive got the jet which is basically identical to the performax. ive had mine for several years now and it's been used quit a bit. im happy to say ive had zero issue like what youve had to deal with. the one difference which probably helped with the breaker and switch issues is mine has the sand smart feature that automatically adjusts the motor under load. heck ive never even had to adjust the belt tracking after the initial setting. id buy this sander again without hesitation. 

working with my hands is a joy,it gives me a sense of fulfillment,somthing so many seek and so few find.-SAM MALOOF.