The primary thing you miss by not using Scheduled Programs on the Ecobee is its Smart Recovery feature, where it will begin heating/cooling in advance of the scheduled program change so you wake up to a warm house, or come home to a cool one. And you can still use program overrides, so that your HVAC goes into Away mode when you leave during the day.
Also note, you don’t have to pay for this ability - there are free alternatives (if I may b so bold) such as the Free Open Source work I recently released here: [RELEASE] The Best FREE Ecobee DTH and Helper SmartApps - Now with Ask Alexa Message Queue Support, and an Enhanced User Experience!
This includes Helper SmartApps that will change your Ecobee Program based on SmartThings Routines or Modes, and/or change SmartThings based on the thermostat (such as setting ST to Away when a scheduled Vacation kicks in on the thermostats).