If you have Eco on you can still welly it by pushing the accelerator all the way to the floor. Not sure how to describe it but when you push the accelerator all the way down there is about an inch further if you push harder. This will give you the full power even if in eco. I recently switched to driving with Eco on to see how much it affected my performance. Bugger all is the answer. I get about 3.4 miles per kW using eco, 3.3 without. And driving with it off is so much more fun!