All of the new kits function exactly like the original EHC EXCEPT :
Differences:
1) Original EHC would not allow starter to engage if ignition (not keyswitch) is in "off" position. New Kit allows this.
2.) Original EHC reverts ignition circuit to "Off" position when keyswitch is turned off/on. New Kit has latching-memory so you don't have to hit "run" if the ignition was turned off by the keyswitch (opposed to the "off" button).
If you are running the stock EHC, you wont need to remove anything except the old EHC and power harness. It does not require removal of the tank or anything like that.
Here is a video of the installation of the new kits: