Jay,
As to "look or biopsy", keep in mind that the doctor is checking for a return of 'non-invasive superficial bladder cancer', which by definition is on the bladder surface. As one school of logic goes, if everything looks OK, then there is nothing to biopsy.
Obviously, your old doc did not find anything at the biopsies, or he would have recommended treatment rather than continuing maintenance.
Unless your former doc had some suspicion of a problem, it is hard to understand the constant biopsies. Perhaps he had a patient who's unremarkable bladder turned sour in a hurry in the past. Or he was just extremely cautious.
As to stretching inspections out to six months, I say "Way to Go". It seems you have the upper hand on the cancer. The training wheels are off, and I hope your ride is smooth until the next checkup.
Best
Jack