I am a first generation adopter (2020) and the system is generally wonderful. Ive upgraded to the Max Battery system. I love my touring bike and I can remove the battery if I want a 'normal' light-weight ride. I also have an off-road bike fitted with the same system. For my daughter's bike I arranged for a mounting clip on the down tube for the battery to keep the centre of gravity lower. She says this has worked well. The customer support was not good in the early days but I think that has gradually improved over time. I'd say steer clear of the Air Battery. it may be suitable for carrying on an aircraft but otherwise pretty useless. I also hated the enhanced switcher since rather than switching up and down through the power ranges, it was cylclic ie you have to go up to level 5 before you can get back to level 1. Stupid Design. I gave mine back to the shop!