I installed the enduralast unit november 2009, rode the bike 40.000 kms in all weather. when it gets really nippy I run gerbings heated jacket, pants, insoles and gloves in addition to the heated grips. even in prolonged inner city commutes the system keeps on top of things.
last fall I had a failure that turned out to be a blown fuse between the alternator and the regulator. the cause: a) I had installed a 10 amp fuse instead of a 20 amp and b) my battery was on it's way out due to age.
replaced the battery and the fuse and all is well again.
I really like this system and the fact that it is brushless.
The endura spark is next on the list.