I now use my bike for journeys I would normally think "oh not today" and throughly enjoy the freedom and ease it provides. I can go into town and bring back quite heavy things that would otherwise have needed a car. It was fairly easy to fit to the bike (although I did get someone to do it for me!). I have the older version with a 2kg battery that is quite heavy and would love the smaller phone size battery that is now being sold. Other than the weight of carrying around my battery, as I wouldn't leave it on the bike when unattended, then it is perfect. Once you start pedalling it engages and you can use as little or as much battery power as you need.