Hi @kvelec4326,
It really depends on your needs.
If you want a feature-complete ecobee3 integration that exposes all API functionalities, then spending $15 or $20 is not much given the development & testing efforts that I’ve put into the device.
Even with the official ecobee3 integration coming, ST will never expose as many features as My Ecobee device. The ST Stock device only exposes less than 10% of the ecobee APIs.
Please refer to this thread to have an idea of the functionalities exposed to you.
Also, If you’re interested in using smart vents later to enable cooling/heating zoned solutions for more comfort at your home, or just want to use any connected ST temp/motion sensors to ajust your ecobee3’s setpoints then My Ecobee device is definitively your solution.
MyEcobee device is not only a device, it’s an ecosystem of smartapps!
Regards.