The cheaper Brooks tend to have thinner leather (as does the swift, at the other end of the price scale,) and they adapt to your shape more quickly. The professional is in my experience the hardest to break in, but I still reckon they are worth it.
A used Brooks usually has been softened by use as well as moulded, so can become comfy quite quickly, I have two that came with bikes, and are lovely now.
The cheaper Brooks tend to have thinner leather (as does the swift, at the other end of the price scale,) and they adapt to your shape more quickly. The professional is in my experience the hardest to break in, but I still reckon they are worth it.
A used Brooks usually has been softened by use as well as moulded, so can become comfy quite quickly, I have two that came with bikes, and are lovely now.