I bought the Air battery and wheel with standard controller. After the quite lengthey wait it turned up the day before Christmas which was very nice. Installing took about 3 to 4 hours but all went very smoothly and within a day I was zooming around. I bought the Swytch specifically to ride my bike to the station which is around 2.5 miles. The journey there is mostly downhill but of course coming back is the killer, basically uphill all the way. After a day at work this is not very appealing to try and ride back on. The Swytch has changed all that. Once I had worked out that just having it on full all time is pointless as it really does kill the battery quickly, I have found the perfect balance of assist for what is a pretty old heavy bike. I redid the PAS sensor after a month or so and found taking the time to align it properly made a massive difference to performance as well. I have invested in a really good lock for the wheel and a separate one for the frame and being on a slightly crappy frame should hopefully fool the thieves. The small battery is then perfect to just slide in my bag with the controller. I love it. I generally was driving before this so I get more exercise, help the environment and have great fun doing it. VV Happy.