I’ve had both and my current LB wheels are with the I9’s. Second set of these hubs. They are very loud, as loud as a Chris King, people always know when I’m around with these and I do love the performance. The 240’s are a more neutral decibel level similar to any Shimano. Both great quality hubs though, the I9’s have a noticeably faster engagement but not sure that truly is needed by the majority of us.