Monitoring NextBus drives me crazy at times too. I check it at about 4:15, as I leave the office at 4:30 and catch the Lawrence-Donway Bus (Which arrives at my stop at exactly 4:30, so I usually time the moment I leave the office so I can catch the bus) I can clearly see when the bus is way ahead of schedule, yet at no point does the bus slow down to get back on schedule. I have missed it so many times because it arrives before the scheduled time.
When I do miss the bus, I walk to Leslie to catch the 51 Leslie, or 54 Lawrence East bus. Again, NextBus shows incredible bunching, yet you never see them attempt to correct the bunching. Leslie has 4-6 buses running the route, and sometimes two will be right behind eachother, leaving a massive gap until the next bus. I've seen a bus held back before, yet it is rarely ever done. It sucks trying to follow a schedule, when the TTC doesn't seem to bother using them itself.
At least we have NextBus now and can actually see whats going on for ourselves. If I had to rely on the TTC's scheduling, I would just drive to work.