I have a 5110 display here, and if it were 6 times bigger, I'd go with it.
But on the handlebar while riding it needs to be bigger to display all the info in a readable size.
If the displays aren't too expensive I wouldn't mind trying a couple of different ones. I bought the blue 20x4 displays aswell and I have a 16x2 I think in green, too.
So, for the prototype I don't mind trying a few different things in hopes I can duplicate them for other bikes later and other people won't have to go through trying everything, too