My first bike had 26" and my second was 29". The first bike corners faster the second was more comfortable. My lap times was very close to the same. I will also mention the 29er does not get unsettled as much (hardtail rider) when I have ridden fast rooty sections. I do not want to buy a bike a year. The wife will kill me! However I will ride one and see. If the 650b is halfway as the "seat of the pants test" vs the actual dimensions, then I will consider it when my bike is wasted, A country boy can survive, but a working man can only pay for so much.