I just sold my RainMachine on eBay and picked up the Rachio on sale from Amazon for $199. I felt Rachio had better integration options with IFTTT and that was my compelling reason to switch over. I want to be able to pause my sprinklers automatically when showering. That is my use case.
I realized the lack of local control was not a big deal as I didn’t use it once in a year of owning the RainMachine. The RainMachine looked cooler but who cares, it’s sitting in my garage! The one thing I will say is the RainMachine seemed to do a better job with weather prediction. For example, it rained about a week ago on and off all morning and the Rachio watered every zone like normal before the rain started. I can bet that the RainMachine would have skipped. Also, RM adjusted every day depending on weather where as the Rachio seems to run the full amount each day. Not sure if that is a big deal as RM might be overanalyzing.
Either way, both controllers are good choices but I felt Rachio offered more support and seemed to have a better backing(RainMachine has been sold out for months without newer inventory). Rachio’s mobile app is superior as it’s much snappier, offers push notifications and historical information and they are coming out with a software update to 2.0 soon. Not sure what RM’s latest update provided though.
Security is a weakness of RM IMO as it requires you to open up ports in your firewall. I never pen tested the device though but still vulnerabilities can be introduced more easily. Rachio is cloud based which some can consider even a more of a security issue but not me.
Rachio offers the ability to connect a rain sensor, RM does not. Personally, I feel rain sensors are pointless with smart irrigation controllers as they should know when to water and when not to.
Lastly, I do have some wifi challenges with my 2.4ghz band in my house and the RainMachine seemed to need to rebooted every once in awhile where as the Rachio seems to have more of a stable wifi signal.