I'm still in the process of getting all the necessary parts of the simulation program working correctly, but I thought I'd start off the thread and get people discussing the ideas.
"Regen" is short for "regenerative braking" and there are those that swear it's the greatest thing since sliced bread. However, there are some downsides to using regen that should be considered if you have a choice of regen verses just using a freewheel. (obviously many people cannot "choose" so regen becomes an option of last resort)
Here are some images to look at and ponder. A freewheel is faster than regen because when you coast without any regenerative braking taking place you go faster. This is what happens when the two types go down a hill. If you are like me and want to actually get somewhere in a hurry (sport riding) then regen seems to offer little benefit.