I don't build many of these as it takes a pretty tough person to really ride one . This is oversize Columbus Spirit tubing and it should behave almost like an aluminum frame with tons of power transfer. That comes with less compliance but for what this bike is built for , all these aspects are what one should expect.
Being that it is steel tubing and much thinner walled than aluminum , it will ride differently. It should be a bit more forgiving over the bumps but it still will be a very stiff ride, especially in this smaller size. I hope that the customer really likes it. It was interesting to build for sure.