I learned and used f/stop printing and split grade printing before I purchased my Stop Clock Pro, using an f/stop chart that I got from Ralph Lambrecht's web site. I believe that I could print just as well with a standard timer and the chart. But the timer makes my darkroom sessions more productive: if I decide, for example, that the highlights need to be just a little darker I can easily and quickly add 1/4 stop to channel 1, for instance. Or if I decide the picture needs a little less contrast I can quickly add 1/3 stop to the highlights on channel 1, and subtract 1/3 stop from the shadows on channel 2. The times for any burns that I have previously worked out are automatically recalculated to the new base times.
The timer is simply a tool that makes me a more efficient printer, reduces math errors, and lets me think more about the product than the process. That said, you would have a fight on your hands if you tried to take it from me!