I'm a massive Klim nerd and own a ridiculous amount of their kit, so I really wanted to love the Ai-1. The concept is excellent, the In&motion technology is well proven and anything that can offer this much additional protection in an accident has to be a good thing. Unfortunately, I just don't find it particularly comfortable. The close fit itself isn't the problem - it's an (underworn) airbag vest and obviously needs to sit fairly snugly against you. My biggest issue is at the back, where the airbag bladder folds around the area where it meets the inflation system. On mine this creates a noticeable lump which presses into my back. I've checked and repositioned everything repeatedly, but it's still there, and once I've noticed it I simply can't un-notice it. For something designed to disappear underneath your normal riding gear, I'm constantly aware that I'm wearing it. The vest also makes a big difference to ventilation. Again, I'm not going to criticise Klim too heavily for the laws of physics - an airtight bladder strapped around your body was never going to improve airflow! As we come into the colder days it's actually quite welcome, but underneath my normally well-ventilated (Klim) kit in summer (like my Marrakesh or Induction jackets) it noticeably defeats some of the point. I've got pretty warm in it. After researching online, I'm not alone in finding the rear of the vest rigid or intrusive, and reduced airflow seems to be a fairly common observation too. It's a shame because otherwise there's a lot I like about it. It's beautifully made, reassuring to wear from a safety point of view, EXTREMELY easy to use and doesn't require a tether to the bike, which in 2026 seems ... rudimentary. The In&motion subscription doesn't particularly bother me either. It can be paused if you're not riding for a period (over winter, for example), and existing users can refer new users for three months free. My referral code is PRFZYLD if anyone buying one wants to use it - that gives both of us three months free! Ultimately though, protective equipment only really works if you wear it. I've tried to get on with the Ai-1 and I really wanted it to become something I automatically put on for every ride, but the pressure against my back and the loss of ventilation mean I find myself sometimes wanting to leave it at home. I promised my wife I'd wear it every trip, so I'm putting up with it, but it's borderline 'send it back to be checked'. For me, unfortunately, that's enough to make it a 2/5. A clever bit of safety equipment that I desperately wanted to love, let down by comfort.