@rakote This thread has some great data on the topic.
I just went to this site and validated what I thought I had for soil type (clay loam). I had no idea this existed!
Silty clay and loam have very similar available water capacity (AWC) while clay loam has a little higher, just meaning that your watering durations will be a little bit longer, but watering frequency will be a little bit lower. These only affect flex schedules which is being rolled out as soon as the 2.0 app is approved.
The other thing soil type affects is smart cycle (run off prevention). This article shows the max allowed run time for nozzle, soil, and slope.
Hope this helps!