I've only been using my Rachio for a couple of weeks and have been impressed.
I did noticed that two schedules when they overlap will cause one to be delayed. For my setup, it would be ideal to have both running at the same time (two watering times running in parallel). The way the water time sequences the zones within a schedule is great.
Second, I'd like to see a dawn or dusk setting to allow for automatics adjustments throughout the year based on the sunrise and sunset.
Keep up the great work