Hi, I have a Rachio 2 in a home I rent to tenants and love it.
Now just bought a new home and want to install a smart controller here. Looking at the website I cannot discern the difference between the model 3 and 3e, apart from a $50 price difference.
Aside from the lack of the 900 Mhz radio (used, so far, only with a discontinued wireless flow meter), 3e does not support flex daily schedule, arguably the most water efficient schedule type. That being said, flex daily does take some experimentation & finetuning to use for the full capacity, if you are derailing with tenants flex monthly will likely be sufficient as set it and forget it setup.