Unfortunately we can't have both (fast booting box + ECO mode) so you have to choose your preference via the Settings > System > ECO mode parameter:

• choose a short value (eg: 30min) if you prioritize ECO savings, which means your Box will be in ECO mode (less than 0.3W) 30min after being in standby, but it will then do a full reboot at wake-up time
• choose a longer period (eg: 48hours) if you prioritize the wake-up speed, as with this setting the TV Box will only go in ECO mode if you're away for a long time, so the wake-up time will be short (a couple of seconds)

• be aware that many TV sets consume a lot of power in active standby (fast wake-up but high energy consumption even in standby), so please check how it is managed from your TV settings
• after a long period without rebooting, the TV Box may become unstable or slow - please reboot it if/when this happens.