I have the YRD240-ZW-619 and it works great. Great battery life (well over a year in vacation property), keyless but with 9V battery contacts on exterior in case batteries in the unit die. I don’t know a lot about the Nest but from what my buddy who has it explained its focus seams to be on a very simple interface and behind the scenes brains to learn your habits.
The ecobee is more of a traditional programmable thermostat with wifi access. I think in a vacation home where you have no habits, the Nest’s learning features might prove less than helpful. For instance I setup the ecobee to basically maintain a low cost away temperature range, and then when the property is occupied I set a hold until canceled more comfortable range. Fancy presence home/away settings don’t really help since on vacation there really is no routine to plan for. My guests might spend the entire day out on the boat, or if its too hot out might retreat back inside during the afternoon hours for a nap. You don’t want them returning to a home in “away” mode and need an hour to return to a comfortable temperature
Guest exit procedure, is where the Smart Home really shines. You can have a routine to turn off all the lights, cancel the hold on the thermostat (resuming away programming), ensure door is locked, turn off electric hot water heater, re-arm SHM, turn security cameras back on (I turn them off while occupied for guest privacy). I fire that off manually since I’m never quite sure when my friends/family are actually leaving until they text me that they have. However if you had a more defined departure time, IFTTT could kick this off for you automatically based on a calendar trigger…
Other automated use cases include moisture sensors at various placed hooked to IFTTT to call me if they detect anything. During the winter I run my dock water agitator (prevents freezing) connected to SmartOutlet. There I can use various weather based triggers to only fire it when weather proves necessary, much more efficient than just programming it to run every so often regardless… As you can see there are tons of vacation property use cases just ensure you’ve always got a fall back option (for me that’s great full-time neighbors). Reliability for these things isn’t here yet to trust as much as you would any non-cloud based solution.