Regardless of how good or bad you might think the Rachio calculations are, it makes sense to test the moisture of the soil in most areas by sampling a small core of soil right after a watering and right before a watering.
This will be the best indication that the water is getting to the correct depth, and also that is it not too dry prior to the start of the next watering.
A simple soil sampler can be purchased OR made from a piece of 1/2" angle iron with a 90 degree bend 24" from the tip. Push it into the soil, twist, and when you remove, the soil will be stuck in the acute angle of the angle iron. It is also easier to remove this soil for the next core test than it is to remove the soil from several commercially available soil core tools.