My wife and I are over 70 and both ride Bromptons so we bought two kits. Swytch seem to be the only supplier for Brompton kits that doesn't require irreversible engineering. This means the kits can be removed and the bikes sold as original should you want to do that. Their pricing makes it a worthwhile upgrade. I’ve had no significant issues fitting the kits and the usability of the bikes with them fitted is very good, although we have yet to do any significant mileage. Folding is unaffected which was significant for us as we wanted to have bikes where we can get both of them into the car boot (mid sized family car). Some care is required in routing the existing front brake cable and gear cable around the battery, also fitting of the pedal sensor can be a little fiddly but once you work that out the rest is straight forward. We've just recently had a holiday in France where we used both bikes effortlessly. Overall I’ve been very pleased with the installation and find riding the bikes quite easy. A couple of minor niggles... The power setup options are many and varied and if I was truthful could do with some simplification but that’s a minor thing. The battery can be difficult to remove from the handlebar attachment and if not carefully positioned can foul against the T-bag which is quite large. Overall very happy however.