I use "normal" as regular mode, also tried "eco" to lessen kick, agree with David Royas to result. I also noticed the bike reverted to "normal" before next ride; anyone else see this? If I want to ride in "eco" or "power" do I have to reset it each time?
I am new owner metro +. 60 or so miles only. Loving it. I have played with the 3 power settings. Eco is fine with me with occasional throttle. I find in Eco, I shift the power assist a bit more, although still only use 1 and 2. The assist seems smoother to me, which I like. After some more miles in Eco, I like it as I work a bit harder, which is the point for me. Throttle is nice at stoplights, in any mode.
Are you looking to enhance the top speed allowed? If so, yes you can change that. There are instructions online, but you can ask the bike store to start the process for you. My bike mechanic made me push the enter button so he could deny doing it.