On the heels of its successful Wi-F-enabled Smart Thermostat, ecobee is set to launch a streamlined version called the Smart Si, in April. And at $250, this looks like an answer to Nest. The new thermostat has a smaller 2.4-inch color touchscreen (versus the Smart Thermostat’s 3.5-inch outchscreen), a push-button interface, controls up to three stages of heating and does not control humidification and dehumidification, like ecobee’s flagship Smart Thermostat. Though it can be used independently or as individual zone control in conjunction with the more feature-laden Smart Thermostat. Ecobee sells through home automation dealers, HVAC installers and builders.