I was quite happy with the first Swytch kit - the second generation ECO model. It performed/performs well, but the battery pack bracket developed a defect that disabled the communication between the pedal sensor and the motor. After much back and forth with Swytch Support, they did replace the battery bracket at no additional cost even though the one-year warranty had expired. The replacement bracket developed the same defect and was replaced again. That was great! Luckily, the this third bracket has not conked out yet (after about 6 months of use). Then came the third generation AIR model. Nicely compact, but the performance was/is very disappointing compared to ECO, particularly during climbs at power levels 3, 2, or 1. At a battery level of 4 it often can't deliver for even a short climb on a paved road and the motor cuts out during the climb. After about a 40 to 75 second "recovery", the battery is able to deliver power, but cuts out again soon there after. It is annoying to say the least and this is one reason I will not purchase a Swytch kit again. While the motor and pedal sensor through successive generations has been (until recently) preserved, the battery pack assembly has not been conserved. I managed to mount the ECO and the AIR on my bike such that I can switch (no pun intended) between the two as needed, but this requires replugging the motor and the pedal sensor. Better than having only to rely on one. Swytch could have offered a compatibility kit to make this possible, but in spite of their innovation, they did not. Also disappointing. Swytch's ticketing system is poor. You can not have more than one open ticket at a time. You often have to communicate with multiple support agents which can be frustrating depending upon how well each one understands the communication and the issues. If you have a real problem (and you know what you are doing), it will take a lot of effort to convince Swytch of a problem and possible solution. Sometimes they close cases before they are verified resolved. Still, they do come through in the end and respond quickly to replies. I had ordered an A-Frame bracket for AIR, but it never came... or was never flawlessly produced. I was given quite a runaround on this for months and in the end demanded a refund, which they granted. Swytch provided a seat bracket at no cost, which was better than nothing, yet not what I wanted. Nevertheless, it has allowed me to use AIR and ECO on the same bike and I am grateful for that.