Yes, because of the stupid turntable. 1:30, the water isn't hot enough. 2:00, the water is too hot and cup is at the back of the oven. The right amount of time, for tap water, in the summer, is 1:47, that puts the water at the front of the oven at the right temp, but I don't want to punch in 1:47, so I just hit the 2 to start and run the oven for 2 minutes, and then pull the door open at 1:47. Also, no beep that way.

Commercial microwaves, like in a restaurant, have a row of numbered buttons that can be programmed for time and power setting. That's the best way to control a microwave.