Running KH, CA,Mg, and PO4 takes me about 30ish mins each time, including equipment cleaning. If I did this once a day (which I don't), it would mean that I'd be spending over 1 week per year on testing my aquarium water.
As one who hates testing water, I chalk this up as a waste of time. The RB costs appx $1000 and I have it setup to make 3,000 tests/year since I'm testing all 4 parameters twice a day. Over the course of 1 year, the cost of this machine comes out to paying RB about $0.12 for every test it runs, which you can probably find in your couch cushions!